MANUAL 

OF 

HYSICAL 
GEOGRAPHY 


WRIGHT 


Tf««««'  J-  ^'"'^' 


THE  LIBRARY 

OF 

THE  UNIVERSITY 

OF  CALIFORNIA 

LOS  ANGELES 


The  RALPH  D.  REED  LIBRARY 

■O 

DEPARTMENT  OF  GEOLOGY 

UNIVERSITY  OF  CALIFORNIA 
LOS  ANGELES,  CALIF. 


3ll<l^  r 


Digitized  by  tine  Internet  Arciiive 

in  2007  witii  funding  from 

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FIELD,   LABORATORY,  AND 
LIBRARY  MANUAL 


IN 


PHYSICAL  GEOGRAPHY 


BY 


C.  T.  WRIGHT,  Ph.B. 

•       Teacher  of  Physical  Geography,  High  School 
Bbdlands,  California 


GINN  &  COMPANY 

BOSTON  .  NEW  YORK  •  CHICAGO  •  LONDON 


COPYKIGHT,   1906,  BY 

C.  T.  WRIGHT 


AliL  BIGHTS  BESEBVBD 
67.11 


g|lt  latftenttum  jpre«« 

GINN   &  COMPANY  •  PRO- 
PRIETORS •  BOSTON  •  U.S.A. 


GeologJl 
Library, 


PEEFACE 

In  offering  this  manual  to  the  public  the  author  wishes  to 
express  the  hope  that  it  may  prove  helpful  to  his  fellow-teach- 
ers, and  that  teachers  and  pupils  alike  may  get  from  it  at  least 
a  portion  of  the  pleasure  that  he  has  taken  in  working  out  its 
exercises.  The  manual  consists  of  readings  and  exercises  selected 
from  those  which  he  has  used  in  his  own  classes  in  the  high 
school.  He  hopes  that  they  may  be  of  value  in  guiding  others 
in  their  first  attempts  at  scientific  investigation  and  research. 

Physical  geography  gives  the  student  a  broader  outlook  than 
any  other  science  in  the  curriculum  of  secondary  schools.  It  is 
a  proper  culmination  of  the  nature  study  of  the  grammar  school, 
and  an  appropriate  introduction  to  the  more  technical  and  rigid 
sciences  of  the  high  school.  Its  value  arises  in  part  from  the 
fact  that  it  "  touches  nature  "  in  so  many  places.  Its  many- 
sidedness  and  its  alluring  bypaths  have  tempted  pupil  and 
teacher  alike.  However  enjoyable  the  physical  side  of  it  may 
be,  it  should  not  be  forgotten  that  it  is  geography.  Its  greatest 
value  arises  from  the  fact  tliat  it  introduces  the  student  to  his 
geographical  environment  and  suggests  to  him  how  he  may 
utilize  it.  Commerce,  history,  and  even  sociology  have  paid 
their  tribute  to  this  study.  The  intimate  and  necessary  relation 
that  exists  between  physical  geography  and  history  is  the  theme 
of  more  than  one  recent  and  valuable  book.  In  this  manual 
economic  phases  have  been  emphasized  throughout. 

In  using  our  eyes  we  sometimes  forget  that  we  may  use  the 
eyes  of  others  to  our  great  pleasure  and  profit.  In  our  attempts 
to  study  geography  at  first  hand  there  is  a  temptation  to  neglect 
the  library.  While  the  author  of  this  manual  would  be  second 
to  none  in  ascribing  value  to  work  done  in  the  field  and  in  the 


691182 


iv  PREFACE 

laboratory,  he  believes  that  there  is  still  a  place  for  our  old 
friend,  the  text-book.  In  order  that  the  text-book  may  not  be 
used  slavishly,  there  have  been  called  into  requisition,  in  Part  I 
of  this  manual,  several  of  the  latest  texts  and  about  fifty  authori- 
tative and  readable  treatises  on  different  phases  of  physical 
geography.  To  prevent  desultory  reading  and  to  avoid  the  dis- 
appointment of  seeking  without  finding,  all  citations  have  been 
made  definite,  indicating  to  the  pupil  where  he  is  to  begin  his 
reading  and  where  to  conclude  it.  Lest  the  pupil  should  read 
much  and  remember  little,  there  have  been  introduced  "  special 
terms,"  which  may  serve  as  nuclei  about  which  he  may  group 
the  truths  of  the  lesson. 

In  the  preparation  of  Part  II  of  this  manual  it  has  been  borne 
in  mind  that  all  "  out  of  doors  "  is  the  real  laboratory  for  the 
study  of  geography ;  but,  on  the  other  hand,  it  has  not  been  for- 
gotten that  the  average  traveler  usually  carries  a  "Baedeker." 
The  ability  to  read  a  landscape  correctly  may  be  of  primary 
importance ;  yet  the  ability  to  read  a  map  correctly  is  invaluable. 
Therefore,  in  this  manual  much  use  has  been  made  of  the  excel- 
lent and  inexpensive  maps  of  the  Geological  Survey,  Coast  and 
Geodetic  Survey,  Hydrographic  Office,  Weather  Bureau,  etc., 
at  Washington.  In  those  exercises  requiring  apparatus  an 
attempt  has  been  made  to  use  only  necessary  and  comparatively 
inexpensive  pieces.  While  the  author  uses  and  recommends  the 
use  of  many  which  are  more  complex  and  expensive,  they  are 
not  referred  to,  partly  because  many  schools  are  not  now 
equipped  with  them,  and  partly  because  this  is  a  pupil's  guide 
and  not  a  guide  for  the  teacher.  The  wise  teacher  will  use  these 
pieces  of  apparatus,  if  available,  in  class  exercises,  and  thus  fur- 
ther whet  the  intellectual  appetite  of  the  pupil. 

First  of  all  the  author  is  indebted  for  inspiration  and  help- 
ful criticism  to  Principal  Lewis  B.  Avery  of  the  Union  High 
School,  Redlands,  California.  Many  valuable  suggestions  have 
come  from  different  members  of  the  California  Physical  Geog- 
raphy Club,  among  whom  should  be  mentioned  Professor  R.  S. 


PREFACE  V 

Holway,  University  of  California ;  Professor  W.  T.  Skilling, 
State  Normal  School,  San  Diego  ;  Miss  Mabel  B.  Pierson,  High 
School,  Pasadena ;  Mr.  C.  S.  Downes,  High  School,  Berkeley ; 
Professor  James  F.  Chamberlain,  State  Normal  School,  Los 
Angeles ;  and  Mr.  George  L.  Leslie,  City  Schools,  Los  Angeles. 
Dr.  Harold  W.  Fairbanks,  of  Berkeley,  California,  has  kindly 
consented  to  the  reproduction  of  twelve  photographs  selected 
from  his  excellent  series  of  lantern  slides. 

The  author  wishes  to  acknowledge  courtesies  extended  by 
Professors  William  Morris  Davis,  Ralph  S.  Tarr,  Albert  Perry 
Brigham,  Charles  R.  Dryer,  and  Alexis  E.  Frye. 

For  any  defects  in  this  manual  the  author  alone  is  responsi- 
ble. Teachers  will  confer  a  favor  if  they  will  suggest  im- 
provements. 

The  author  will  be  pleased  to  cooperate  with  teachers  in  the 
matter  of  furnishing  lantern  slides  and  other  supplies. 

C.  T.  WRIGHT 
Redlands,  California 
April,  1906 


CONTENTS 


PART  I.     LIBRARY  MANUAL 

Chapter  Pagk 

I.  The  Earth  among  Planets 3 

IL  The  Atmosphere    .........  6 

III.  Winds  and  Storms .  8 

IV.  Climate 13 

V.  The  Structure  of  the  Earth        .......  15 

VI.  Disintegration  and  Erosion  .......  19 

VII.  Rivers 21 

VIII.  Land  Forms  due  to  Other  Agencies 25 

IX.  Imperfect  Drainage  .........  30 

X.  Underground  Waters    ........  32 

XL  The  Ocean 34 

XII.  Coast  Forms 37 

XIII.  Minerals  and  Rocks          ........  39 

XIV.  Weathering  and  Soils  .         .         .         .         .         .         .         .43 

XV.  Plants,  Animals,  and  Man 46 

PART  II.     FIELD  AND  LABORATORY  MANUAL 


Exercise 

I.  Magnitudes  and  Distances 
II.  The  Oblateness  of  the  Earth 

III.  The  Direction  of  the  Axis  of  the  Earth's  Rotation 

IV.  Lengths  of  Day  and  Night    . 
V.  North  and  South  Line 

VI.  The  Apparent  Movements  of  the  Sun 

VII.  The  Moon 

VTII.  Latitude 

IX.  Some  Proi>erties  of  the  Atmosphere 

X.  Constituents  of  the  Atmosphere    . 
XL  Combustion  and  Oxidation 
XIT.  Evaporation  and  Condensation 

XIIL  Humidity 

XIV.  Light 

XV.  Magnetism         ..... 


55 
56 
58 
59 
60 
61 
64 
65 
66 
67 
68 
69 
70 
74 
76 


viii  CONTENTS 

ExEBCisE  Page 

XVI.  Isotherms 77 

XVII.  The  Barometer 83 

XVIII.  Isobars 83 

XIX.  Observations  of  the  Weather    ......     86 

XX.  Prevailing  Winds 87 

XXI.  Winds  in  a  Cyclone 88 

XXII.  Areas  of  Precipitation  ......  89 

XXIII.  Temperatures  in  Cyclones  and  Anticyclones      .         .         .90 

XXIV.  Movements  of  Low  Barometer  in  the  United  States      .  91 
XXV.  Weather  Forecasting 92 

XXVI.  Rainfall .  93 

XXVII.  Zones  of  Climate 96 

XXVIII.  Elevations  and  Depressions  of  the  Earth's  Surface  drawn 

to  Scale 98 

XXIX.  Contour  Lines .99 

XXX.  Contour  Maps 101 

XXXI.  The  Weathering  of  Rocks 102 

XXXII.  The  Assorting  Power  of  Water    .         .         .         .         .  105 

XXXIII.  Examination  of  Rock  Waste 105 

XXXIV.  A  Waterfall 106 

XXXV.  River  Flood  Plains 107 

XXXVI.  Meanders 110 

XXXVII.  Alluvial  Cones 112 

XXX VIIL  A  Region  in  Youth 114 

XXXIX.  A  Region  in  Maturity .117 

XL.  A  Region  in  Old  Age 119 

XLI.  The  Life  History  of  a  River 120 

XLII.  The  Drainage  Areas  of  the  United  States     .         .         .120 

XLIII.  The  Migration  of  Divides 120 

XLIV.  Specific  Gravity 122 

XLV.  Volcanic  Rocks 123 

XL VI.  Volcanic  Peaks,  Plateaus,  and  Necks    .         .         .         '123 

XLVII.  A  Crater 126 

XL  VIII.  Glaciers 127 

XLIX.  Topographic  Forma  due  to  Glaciation       .         .         .         .128 
L.  Lakes    ..........       131 

LI.  Extinct  Lakes 134 

LII.  Solids  in  Solution 135 

LIII.  Veins 137 

LIV.  Density  and  Temperature  of  Sea  Water  .     .         .         .        139 

LV.  Tides .         .140 

LVI.  Ocean  Currents 142 


CONTENTS 


iJc 


Exercise 

LVII.  Icebergs       .... 
LVIII.  The  Sea  and  Man    . 
LIX.  Headlands,  Beaches,  Sea  Caves 
LX.  Barrier  Beaches 
LXI.  Drowned  and  Elevated  Coasts 

LXII.  Harbors 

LXni.  Economic  Minerals  and  Ores 
LXIV.  Limestone        .... 

LXV.  Coal 

LXVI.  Granite 

LXVn.  Fragmental  Rocks 
LXVni.  Building  Stone 
LXIX.  Decomposing  Agents    . 
LXX.  Irrigation         .... 


Page 
.  144 

145 
.  148 

150 
.  152 

154 
.  155 

156 
.  157 

159 
.  160 

163 
.  164 

165 


APPENDIX 


List  of  Text-Books 167 

List  of  Reference  Books  .         .         .         .         .         .         .         .167 

List  of  Government  Maps    .........  170 

List  of  Apparatus  and  Supplies       .......        172 

Index         . 173 


LIST  OF  ILLUSTRATIONS 

Pio.  Page 

1.  The  Clinometer 61 

2.  A  Bar  Magnet  (mounted) 76 

3.  Isothermal  Lines  of  the  World  for  July         .         .         .         .         .79 

4.  Isothermal  Lines  of  the  World  for  January      ....  81 

5.  Average  Annual  Rainfall  of  the  World         .         .         .         .         .94 

6.  Annual  Range  of  Temperature  ......  97 

7.  A  Hypsometric  Map  of  the  United  States      .         .   between  98  and  99 

8.  A  Landscape    ..........        100 

9.  Ilachure  Map  of  the  Same  Region         ......  100 

10.  Contour  Map  of  the  Same  Region     ......        101 

11.  A  Profile  from  Contour  Map 101 

12.  A  Cofitour  Map  of  San  Pedro  Hill,  California  ...        103 

13.  Apparatus  for  showing  the  Effect  of  Heat  on  Iron  .  .  .  104 
11.  The  Flood  Plain  of  the  Merced  River,  California  ...  109 
15.  A  Debris  Fan  at  Glenwood  Springs,  Colorado  .  .  .  .113 
IG.  A  Terrace  cut  by  the  Santa  Ana  River,  California    .         .         .        115 

17.  The  Canyon  of  the  Yellowstone 116 

18.  IMud  Cracks  in  the  Bed  of  an  Intermittent  Stream   .         .         .        124 

19.  Columns  of  Basalt,  North  Fork  of  San  Joaquin  River  .         .         .  125 

20.  Section  of  a  Glacial  Moraine     .         .         .         .         .         .         .129 

21.  Belts  of  Vegetation  about  a  Pond 130 

22.  Bear  Lake,  showing  no  Zones  of  Vegetation      .         .         .         .132 

23.  Map  of  the  Ancient  Lake  Bonneville     ......  133 

24.  Map  of  the  Bed  of  the  Ancient  Salton  Sea        ....        134 

25.  Contour  Map  of  the  Dead  Sea       .         .         .         .         .         .         .135 

26.  A  Beaker  arranged  for  the  Formation  of  Crystals     .         .         .        136 

27.  A  Bottle  and  Siphon  arranged  for  the  Formation  of  Stalactites        .  137 

28.  A  Rock  with  Intersecting  Veins        ......        138 

29.  Winds  of  the  World  for  January  ......  141 

30.  Chart  of  Ocean  Currents 143 


xii  LIST  OF  ILLUSTRATIONS 

Fig.  Page 

31.  Avalon  Bay,  Santa  Catalina  Island,  California      ....  146 

32.  A  Rocky  Headland 147 

33.  Sea  Caves  at  La  JoUa,  California  ......  148 

34.  An  Arch  cut  by  Waves     ........        149 

35.  Sand  Reefs  off  the  Coast  of  North  Carolina  .         .         .         .         .150 

36.  Sand  Reefs  off  the  Coast  of  Texas    .         .         .         .         .         .151 

37.  Terraces  cut  by  the  Sea  at  Point  San  Pedro,  California         .         .  152 

38.  A  Double  Pebbly  Beach 153 

39.  A  Church  built  of  Coral 156 

40.  A  Petrified  Tree 158 

41.  A  Young  Tree  growing  from  a  Crack  in  Granite  ....  161 

42.  A  Weir  on  the  Truckee  River,  Nevada 161 

43.  A  Flume  near  Redlands,  California      ......  162 

44.  A  Laboratory  for  Physical  Geography       .         .         .         .         .166 

45.  Pupils'  Work  Table  for  Physical  Geography  .         .         .         .169 

46.  Teacher's  Cabinet  Table  for  Physical  Geography       .         .         .       171 


PHYSICAL  GEOGRAPHY  MANUAL 

Part  I 
LIBRARY  MANUAL 


LIBRARY  MANUAL 

CHAPTER  I 
THE  EARTH  AMONG  PLANETS 

1.  THE  SOLAR  SYSTEM 
EXERCISE  I.    Magnitudes  and  Distances 

Text-books.^  Davis,  8-9.  Davis  El e.,  11-14.  Gilbert  and  Brigham, 
17-18.    Redway,  9-12.    Tarr,  3-6,  9-10. 

Reference  books. ^  Davis,  Elementary  Meteorology:  2-3*,'  The  neb- 
ular hypothesis. 

Fairbanks,  Rocks  and  Minerals :  13-17,  The  beginning  of  the 
earth. 

Newcomb,  Elements  of  Astronomy :  32-34,  The  earth  as  a  planet; 
153-156,  Venus ;  156-159,  Mars ;  160-161,  The  asteroids ;  162-167, 
Jupiter;  167-171,  Saturn;  172-175,  Uranus  and  Neptune;  176- 
186,  Comets  ;  187-190,  Meteors. 

Shaler,  Outlines  of  the  Earth'' s  History:  33^-39*,  The  nebular 
hypothesis. 

Young,  Lessons  in  Astronomy:  204-208,  Mercury;  209-214, 
Venus;  215-224,  Mars;  225-230,  The  asteroids;  232-238,  Jupi- 
ter; 239-245,  Saturn;  245-250,  Uranus  and  Neptune;  348-353, 
Cosmogony. 

Special  terms.  Star,  planet,  satellite,  asteroid,  orbit,  circle,  ellipse, 
diameter,  radius,  solar  system. 

1  See  List  of  Text-Books  in  Appendix. 

2  See  List  of  Reference  Books  in  Appendix. 

8  Small  letters  appearing  at  the  right  of  the  figures  indicate  parts  of  pages, 
as  follows :  a,  first  half  of  page ;  6,  second  half  of  page ;  c,  beginning  near  the 
bottom  of  the  page. 

3 


4  PHYSICAL  GEOGRAPHY  MANUAL 

2.  THE  FORM  OF  THE  EARTH 
EXERCISE  n.   The  Oblateness  of  the  Earth 

Text-books.  Davis,  10-14.  Davis  Ele.,  1-6.  Dryer,  9-12.  Gilbert 
and  Brigham,  1-2.    Eedway,  12-13.    Tarr,  1-3. 

Reference  books.  Newcomb,  Elements  of  Astronomy:  17-19, 
Change  of  horizon  as  we  travel ;  80-89,  Gravitation. 

Young,  Lessons  in  Astronomy:  78-81,  Porm,  size,  and  measure- 
ment of  the  earth ;  84^-86*,  Effects  of  the  earth's  rotation  on  its  form. 

Special  terms.  Horizon,  curved  surface,  uniformly  curved  surface, 
plane  surface,  sphere,  spheroid,  oblate  spheroid,  eclipse. 

3.  MOTIONS  OF  THE  EARTH 
EXERCISE  III.   The  Direction  of  the  Axis  of  Rotation 

Text-books.  Davis,  15-16.  Davis  Ele.,  6-8.  Dryer,  13-18.  Gil- 
bert and  Brigham,  18-20.    Eedway,  13-14.    Tarr,  6-9. 

Reference  books.  Young,  Lessons  in  Astronomy :  81-82,  The  rota- 
tion of  the  earth ;  83-84,  Invariability  of  the  earth's  rotation ;  95, 
Changes  in  the  earth's  orbit. 

Special  terms.  Apparent  path  of  the  sun,  revolution,  rotation, 
axis,  cardinal  points,  up,  down,  zenith,  nadir,  antipodes,  light, 
shadow,  day,  year,  gravitation,  centrifugal  force. 

4.  INCLINATION  OF  THE  EARTH'S  AXIS 
EXERCISE  IV.   Lengths  of  Day  and  Night 

Text-books.  Davis  Ele.,  46-52.  Dryer,  19-22.  Gilbert  and 
Brigham,  20-25.    Redway,  14.    Tarr,  397-401. 

Reference  books,  l^ewcomh,  Mements  of  Astronomy:  23-28,  Diur^ 
nal  motions  in  different  latitudes ;  34-37,  Motions  and  seasons. 

Waldo,  Elementary  Meteorology:  22-24,  Inclination  of  the  earth's 
axis  of  rotation. 

Young,  Lessons  in  Astronomy:  96-97,  Seasons;  98-99,  Effects  of 
inclination  on  temperature. 


THE  EARTH  AMONG  PLANETS  5 

Special  terms.  Parallel,  horizontal,  perpendicular,  vertical,  pole 
star,  plane  of  orbit,  inclination,  great  circle,  small  circle.  Tropic  of 
Cancer,  Tropic  of  Capricorn,  Arctic  Circle,  Antarctic  Circle,  zone, 
width  of  zone,  equinox,  solstice,  season. 

5.  THE  SUN 
EXERCISE  V.   North  and  South  Line.    VI.    The  Apparent  Movements  of  the  Sun 

Reference  books.  Newcomb,  Elements  of  Astronomy :  37-41,  Appar- 
ent motion  of  the  sun ;  103-111,  The  sun. 

Young,  Lessons  in  Astronomy:  134-138,  The  sun's  surface;  138- 
144,  Sun  spots;  156-161,  Chromosphere,  prominences,  corona; 
166-169,  The  heat  of  the  sun. 

6.  THE  MOON 
EXERCISC  VII.   The  Moon 

Text-books.    Redway,  11  (picture).    Tarr,  9  (picture). 

Reference  books.  Newcomb,  Elements  of  Astronomy :  112-116,  Dis- 
tance, size,  and  aspects  of  the  moon ;  118-120,  Tlie  moon's  phases 
and  rotation  ;  123-125,  Eclipses  of  the  moon  ;  126-131,  Eclipses  of 
the  sun. 

Shaler,  Aspects  of  the  Earth :  89*-92,  The  craters  of  the  moon. 

Young,  Lessons  in  Astronomy :  113-114,  Rotation  of  the  moon; 
114—116,  Phases  of  the  moon;  116-117,  Earthshine  on  the  moon; 
117-118,  Absence  of  air  and  water  on  the  moon  ;  118-119,  Light 
and  heat  of  the  moon ;  120-125,  Telescopic  appearance  and  surface 
structure;  173-175,  Lunar  eclipses  ;  175-179,  Eclipses  of  the  sun. 

Special  terms.    Phase,  eclipse,  reflection. 

7.  LATITUDE  AND  LONGITUDE 

EXERCISE  Vm.    Latitude 

Text-books.  Davis,  388-393.  Davis  Ele.,  8-11.  Dryer,  23-25. 
Gilbert  and  Brigham,  2-4.    Tarr,  402-405. 


6  PHYSICAL  GEOGRAPHY  MANUAL 

Reference  books.  Newcomb,  Elements  of  Astronomy:  52-55,  Longi- 
tude and  time ;  90-97,  Measurements  of  the  earth. 

Special  terms.  Latitude,  longitude,  equator,  prime  meridian,  Mer- 
cator's  projection,  conical  projection,  stereographic  projection. 


CHAPTER  II 

THE  ATMOSPHERE 

8.  PHYSICAL  PROPERTIES  OF  THE  ATMOSPHERE 

EXERCISE  IX.    Some  Properties   of  the   Atmosphere.      X.    Constituents   of  the 
Atmosphere.      XI.    Combustion  and  Oxidation 

Text-books.  Davis,  22-26.  Davis  Ele.,  23-24,  27-29.  Dryer, 
273-279.  Gilbert  and  Brigham,  223-226.  Redway,  214-216.  Tarr, 
229-232. 

Reference  books.  Davis,  Elementary  Meteorology :  3-4,  Evolution 
and  future  of  the  atmosphere ;  4-5,  Composition  of  the  atmosphere ; 
6-7,  Oxygen  and  carbonic  acid  as  related  to  plants  and  animals ; 
T'^-S,  Economic  aspects  of  the  atmosphere ;  13^^-14,  Height  of  the 
atmosphere. 

Fairbanks,  Rocks  and  Minerals:  119-121,  The  work  of  oxygen  ; 
122-125,  Carbon,  nitrogen,  and  hydrogen. 

Shaler,  Aspects  of  the  Earth :  204 ''-209,  Gases  in  the  atmosphere. 

Shaler,  Outlines  of  the  Earth^s  History :  98-99,  Composition  and 
height  of  the  atmosphere. 

Waldo,  Elementary  Meteorology :  7-9,  Constituents  of  the  air. 

Special  terms.  Weight,  elasticity,  transparency,  pressure,  density, 
oxygen,  hydrogen,  nitrogen,  carbon  dioxide. 

9.  HUMIDITY,  EVAPORATION,  CONDENSATION 

EXERCISE  Xn.    Evaporation  and  Condensation.     XIII.    Humidity 

Text-books.  Davis  Ele.,  60-62.  Dryer,  280-282.  Gilbert  and 
Brigham,  226-227.    Redway,  231-233.    Tarr,  244-245. 


THE  ATMOSPHERE  7 

Reference  books.  Harrington,  About  the  JVeather :  66-72,  Humid- 
ity, or  moisture  ;  227,  The  thermometer  ;  227'=-231,  The  hygrometer, 

Shaler,  Outlines  of  the  EartKs  History :  156''-159*,  Evaporation 
and  condensation. 

Waldo,  Elementary  Meteorologij :  31-32,  Thermometers;  118-121, 
Moisture  of  the  atmosphere ;  122-124,  Humidity ;  163-165,  Evap- 
oration. 

Special  terms.  Water  vapor,  evaporation,  humidity,  relative 
humidity,  absolute  humtdity,  thermometer,  wet  bulb  thermometer, 
hygrometer,  saturation,  condensation,  precipitation. 


10.  DEW,  FROST,  FOG,  CLOUDS 

Text-books.  Davis,  47,  403-404.  Davis  Ele.,  61-64.  Dryer,  282- 
286.  Gilbert  and  Brigham,  227-230.  Redway,  233-238.  Tarr, 
246-248. 

Reference  books.  Harrington,  About  the  Weather:  73-91,  Dew, 
fog,  cloud. 

Shaler,  Outlines  of  the  Earth's  History:  159-164,  Dew,  clouds. 

Waldo,  Elementary  Meteorology :  129-135*,  Clouds ;  162,  Dew, 
frost. 

11.  RAIN,  SNOW,  HAIL 

Text-books.  Davis,  45.  Davis  Ele.,  38-39,  70.  Dryer,  285,  327. 
Gilbert  and  Brigham,  230-231.  Redway,  238,  242-243.  Tarr, 
249-250. 

Reference  books.  Harrington,  About  the  Weather:  92-98,  Precipi- 
tation :  rain  and  snow ;  166-173,  Storms  of  ice,  sleet,  ball  snow, 
and  hail. 

Muir,  Mountains  of  California  :  41-47,  Snow  banners  from  moun- 
tain peaks  ;  123,  Snow  buries  lakes  in  winter  ;  38,  Snow  and  sludge 
bridge  a  stream  in  winter. 

Shaler,  Outlines  of  the  Earth's  History:  207''-208,  Snow  as  a  pro- 
tective covering. 

Waldo,  Elementary  Meteorology :  142-144,  Rain  ;  159-161,  Hail, 
snow. 


8  PHYSICAL  GEOGRAPHY  MANUAL 

12.  LIGHT 
EXERCISE  XIV.    Light 

Text-books.  Davis  Ele.,  27,  30,  63,  66.  Gilbert  and  Brigham,  237. 
Redway,  277-281.     Tarr,  232-233. 

Reference  books.  Waldo,  Elementary  Meteorology:  166-169,  Re- 
fraction, reflection,  diffraction ;  169,  Mirage ;  170-171*,  Colors  of 
the  sky ;  171-174*,  Coronas  and  halos  ;  174'*-175*,  Rainbows. 

Special  terms.  Reflection,  refraction,  diffraction,  spectrum,  rain- 
bow, halo,  corona,  mirage. 

13.  MAGNETISM  AND  ELECTRICITY 
EXERCISE  XV.    Magnetism 

Text-books.  Davis,  398-399.  Davis  Ele.,  17-19.  Gilbert  and 
Brigham,  274-27^.     Redway,  272-277.     Tarr,  418-419. 

Reference  books.  Shaler,  Outlines  of  the  Earth's  History:  168, 
Aurora  borealis. 

Waldo,  Elementary  Meteorology:  175-179,  Atmospheric  elec- 
tricity. 

CHAPTER  III 

WINDS  AND  STORMS 

14.  INSOLATION,  TEMPERATURE,  ISOTHERMS 

EXERCISE  XVI.    Isotherms 

Text-books.  Davis,  27-28.  Davis  Ele.,  31-35.  Dryer,  293-300. 
Gilbert  and  Brigham,  238-252. 

Reference  books.  Davis,  Elementary  Meteorology :  18,  Radiation 
from  the  sun. 

Dodge,  Reader  in  Physical  Geography :  176-180,  Temperature. 

Harrington,  About  the  Weather:  60-65,  The  temperature  of  the 
air  ;  187-193,  The  weather  progress  through  the  day  and  year. 


WINDS  AND  STORMS  9 

Waldo,  Elementary  Meteorology :  25''-30,  Insolation ;  31^5, 
The  thermometer  ;  36-39,  Regular  diurnal  change  of  temperature  ; 
40,  Average  daily  temperature  ;  50-58,  Isotherms. 

15.  ATMOSPHERIC  PRESSURE 
EXERCISE  XVn.    The  Barometer.     XVm.    Isobars 

Text-books.  Davis,  23-24.  Davis  Ele.,  24-27.  Dryer,  301-304. 
Gilbert  and  Brigham,  253-256. 

Reference  books.  Harrington,  About  the  Weather:  33-40,  The 
pressure  of  the  air  and  how  it  is  measured  ;  41-47,  Changes  in  the 
pressure  of  the  air  ;  223-227*,  Barometers. 

Waldo,  Elementary  Meteorology:  73-77,  Atmospheric  pressure 
and  the  barometer. 

Special  terms.  Weight,  pressure,  barometer,  isobar,  low  barom- 
eter, high  barometer. 

16.  GENERAL  MOVEMENTS  OF  THE  ATMOSPHERE 
EXERCISE  XIX.    Observations  of  the  Weather.     XX.    PrevaiUng  Winds 

Text-books.  Davis,  29-33.  Davis  Ele.,  35-38,  53-58.  Dryer,  287- 
292,  306-311.  Gilbert  and  Brigham,  256-258,  266-268.  Redway, 
219-220.     Tarr,  258-262.  • 

Reference  books.  Dodge,  Reader  in  Physical  Geography:  185- 
188,  Winds. 

Harrington,  Mout  the  Weather :  48-56,  Winds  —  their  kinds  and 
distribution  ;  56-59,  Measurement  of  the  wind. 

Shaler,  Aspects  of  the  Earth :  212-222,  Winds. 

Shaler,  First  Book  in  Geology :  56-61,  Air  ;  98-101,  General 
movements  of  the  atmosphere. 

Shaler,  Outlines  of  the  Earth's  History :  101-106*,  Currents  of 
the  air. 

Waldo,  Elementary  Meteorology:  101-104,  Movements  of  the 
atmosphere ;  187-191,  General  circulation  of  the  atmosphere. 


10  PHYSICAL  GEOGRAPHY  MANUAL 

17.  TRADE  WINDS 

Text-books.  Davis,  30.  Davis  Ele.,  39-44.  Dryer,  306.  Gilbert 
and  Brigham,  259-260.     Redway,  218.     Tarr,  259-260. 

Reference  books.  Harrington,  About  the  Weather :  136-141,  Effects 
of  the  earth's  rotation  upon  the  direction  of  the  winds. 

Shaler,  Fh-st  Book  in  Geology :  101-102,  Trade  winds. 

Waldo,  Elementary  Meteorology :  195^-198%  Effect  of  the  earth's 
rotation  on  air  currents ;  208-212,  Trade  winds,  monsoons,  doldrums. 


18.  CYCLONES  AND  ANTICYCLONES 

EXERCISE  XXI.    Winds  in  a  Cyclone.     XXn.    Areas  of  Precipitation. 
XXIII.    Temperatures  in  Cyclones  and  Anticyclones 

Text-books.  Davis,  33-34.  Davis  Ele.,  44-46,  74-81.  Dryer,  304- 
306,  312-317.  Gilbert  and  Brigham,  258-259.  Redway,  248-250. 
Tarr,  262-267. 

Reference  books.  Harrington,  About  the  Weather:  99-109,  General 
storms,  cyclones,  or  lows  ;  110-116,  Condensation  in  a  cyclone  ;  128- 
135,  The  weather  brought  by  the  cyclone ;  142-147,  Anticyclones, 
or  highs. 

Shaler,  Aspects  of  the  Earth :  246-250,  Cyclones ;  250-255,  Oceanic 
cyclones. 

Shaler,  Outlines  of  the  Earth^s  History :  111-112,  Cyclones. 

Waldo,  Elementary  Meteorology :  216-227*,  Cyclones ;  234<'-240, 
Anticyclones. 


19.  MOVEMENTS  OF  LOW  BAROMETER  IN  THE 
UNITED  STATES 

EXERCISE  XXIV.    Movements  of  Low  Barometer  in  the  United  States 

Text-books.  Davis,  49«-51,  Davis  Ele.,  79.  Dryer,  317-318,  343. 
Gilbert  and  Brigham,  260.    Redway,  260. 

Reference  books.  Harrington,  About  the  Weather :  117-127,  Cyclones 
travel  eastward. 


WINDS  AND  STORMS  11 

20.  HURRICANES.  — TROPICAL  CYCLONES 

Text-books.  Davis,  38-40.  Davis  Ele.,  67-69.  Dryer,  318-321. 
Gilbert  and  Brigham,  265-266.    Redway,  250.    Tarr,  269-271. 

Reference  books.    Russell,  North  America :  209-212,  Hurricanes. 

^h\i\ev,  OntUnes  of  the  Earth^s  History :  106''-110,  Hurricanes. 

Waldo,  Elementary  Meteorology:  229-230,  Hurricanes  and 
typhoons. 

21.  WEATHER  FORECASTING 

EXERCISE  XXV.    Weather  Forecasting 

Text-books,  Davis,  62.  Davis  Ele.,  81-82.  Gilbert  and  Brigham, 
268-269.    Redway,  259-261. 

Reference  books.  Harrington,  About  the  Weather :  xiii-xvi.  Weather 
prediction  is  a  science ;  17-32,  Economic  aspects  of  the  weather ; 
203-210,  Weather  predictions  as  a  remedy  against  weather  injuries  ; 
211-222,  The  progress  of  knowledge  of  the  weather. 

Garriott,  Weather  Folk-Lore  and  Local  Weather  Signs :  5-28, 
Weather  folk-lore ;  29-47,  Long-range  weather  forecasts ;  49-153, 
Local  weather  signs  ;  Charts  I-XXI,  Winds,  clouds,  barometric 
pressure. 

Garriott,  Long-Range  Weather  Forecasts :  3-4,  Letter  of  trans- 
mittal and  general  statement ;  7-10,  Verification  of  long-range 
weather  forecasts ;  11-31,  The  planetary  equinoxes ;  37-68,  Dis- 
cussion of  long-range  weather  forecasts. 

Kenealy,  Weather  Bureau  Stations  and  their  Duties:  109-110, 
Origin  and  development  of  the  meteorological  service ;  110''-112*, 
The  daily  weather  forecasts  ;  115-120,  The  duties  performed  at  the 
stations. 

Waldo,  Elementary  Meteorology:  276-282%  Weather  maps; 
282''-292,  Weather  predictions. 

22.  TORNADOES 

Text-books.  Davis,  34.  Davis  Ele.,  66-67.  Dryer,  323-325.  Gil- 
bert and  Brigham,  265.    Redway,  255-259.  •  Tarr,  267-269. 


12  PHYSICAL  GEOGRAPHY  MANUAL 

Reference  books.  Harrington,  About  the  Weather:  156-165,  Tor- 
nadoes or  intense  local  whirls. 

Russell,  North  America:  207-208,  Tornadoes. 

Shaler,  Aspects  of  the  EaHh :  234-246,  Tornadoes. 

Shaler,  Outlines  of  the  EartKs  History:  112'*-115,  Tornadoes; 
115'>-117%  Waterspouts. 

Shaler,  Story  of  Our  Continent :  130-132,  Violent  storms  of  North 
America. 

Waldo,  Elementary  Meteorology :  241-249,  Tornadoes;  259''-261, 
Spouts. 

23.  THUNDERSTORMS 

Text-books.  Davis  Ele.,  65.  Dryer,  325-326.  Gilbert  and  Brig- 
ham,  264-265.    Redway,  271. 

Reference  books.  Harrington,  About  the  Weathef:  174-179,  Thun- 
derstorms and  cloud-bursts. 

Russell,  North  America :  206-207,  Thunderstorms. 

Shaler,  Outlines  of  the  Earth'' s  History :  164^-167%  Thunderstorms. 

Waldo,  Elementary  Meteorology :  249*^-259,  Thunderstorms. 

24.  LOCAL  WINDS 

Text-books.  Davis,  44.  Davis  Ele.,  58-60.  Gilbert  and  Brigham, 
262-264.    Redway,  222-224.    Tarr,  256-257. 

Reference  books.  Harrington,  About  the  Weather :  148-155,  "  Be- 
twixt and  between  weather";  194-202,  Local  influences  of  the 
winds. 

Shaler,  Aspects  of  the  Earth :  223-226,  Land  and  sea  breezes. 

Shaler,  Outlines  of  the  Earth^s  History:  118*'-121*,  Land  and  sea 
breezes. 

Waldo,  Elementary  Meteorology:  262-263,  Periodic  local  winds; 
263''-268,  Miscellaneous  winds. 


CLIMATE  13 

CHAPTER  IV 

CLIMATE 

25.  FACTORS  OF  CLIMATE 

Text-books.  Davis,  297-298.  Dryer,  335-336.  Gilbert  and 
Brighain,  270.    Redway,  287-290.    Tarr,  275-279. 

Reference  books.  Dodge,  Reader  in  Physical  Geography :  171-175, 
Weather  and  climate. 

Moore,  Climate,  Its  Physical  Basis  and  Controlling  Factors:  7, 
Weather  and  climate ;  7-10,  Basis  of  climate. 

Waldo,  Elementary  Meteorology :  269-275,  Weather  conditions ; 
293-301,  Climatift  conditions. 

26.  RAINFALL 
EXERCISE  XXVI.    Rainfall 

Text-books.  Davis,  45-47.  Davis  Ele.,  70-74.  Dryer,  327-334. 
Gilbert  and  Brigham,  231-236. 

Reference  books.  Dodge,  Reader  in  Physical  Geography :  188-193, 
Moisture  and  rainfall. 

Henry,  Average  Annual  Precipitation  in  the  United  States :  207- 
213,  Data  for  the  period  1871  to  1901,  with  two  maps, 

Waldo,  Elementary  Meteorology :  148-166,  Geographical  distribu- 
tion of  annual  rainfall. 

27.  ZONES  OF  CLIMATE 
EXERCISE  XXVn.    Zones  of  Climate 

Text-books.  Davis,  52-53.  Davis  Ele.,  82-85.  Dryer,  336-348. 
Gilbert  and  Brigham,  246-250.    Redway,  291-298.    Tarr,  279-289. 

Reference  books.  Dodge,  Reader  in  Physical  Geography :  180-184, 
Zones  and  heat  belts ;  194-197,  Seasons  and  climate  in  different 
parts  of  the  world. 


14  PHYSICAL  GEOGRAPHY  MANUAL 

Russell,  iVbriA  America:  186-191,  The  climate  of  Mexico  and 
Central  America ;  191-194,  The  climate  of  the  Atlantic  and  Gulf 
states ;  194-201,  The  climate  of  central  North  America ;  201-203, 
The  climate  of  northern  North  America. 

Waldo,  Elementary  Meteorology :  SOl^'-SOG,  Climatic  zones  ;  307- 
312,  Climates  of  the  continents. 

28.  CHANGES  OF  CLIMATE 

Text-books.    Davis,  298.    Davis  Ele.,  288-290. 

Reference  books.  Moore,  Climate,  Its  Physical  Basis  and  Con- 
trolling Factors :  10-15,  Variations  in  climate. 

Waldo,  Elementary  Meteorology:  48,  Long-period  temperature 
oscillations. 

29.  CHANGES  OF  CLIMATE  IN  PAST  GEOLOGICAL  AGES 

Text-books.  Davis,  330-333.  Gilbert  and  Brigham,  143-146. 
Redway,  290-291.     Tarr,  147. 

Reference  books.  Jordan,  Science  Sketches :  224-231,  The  story  of 
a  stone. 

Shaler,  First  Book  in  Geology :  46-55,  Coal  and  the  coal  age. 

Shaler,  Outlines  of  the  EartKs  History :  235,  Warm  weather  at 
the  poles  ;  244*'-247*,  Causes  of  a  glacial  period. 

Tarr,  Economic  Geology  of  the  United  States :  326-331,  Conditions 
existing  in  Carboniferous  times. 

30.  CLIMATIC  REGIONS  OF  THE  UNITED  STATES 

Text-books.  Dryer,  341-346.  Gilbert  and  Brigham,  270-272. 
Tarr,  291-293. 

Reference  books.  Fairbanks,  Western  United  States :  249-258,  The 
climate  of  the  Pacific  coast. 

Shaler,  Story  of  Our  Continent:  123-130,  Climate  of  North 
America ;  169-171,  The  frozen  north  ;  171''-174%  The  arid  regions  ; 
174-176*,  North  America  compared  with  other  continents ;  176- 
178,  Central  United  States ;  178^-183,  Atlantic  and  Pacific  coasts 
compared. 


THE  STRUCTURE  OF  THE  EARTH       15 

"Waldo,  Elementary  Meteorology :  313-321,  Climatic  regions  of 
the  United  States ;  322-335,  Geographical  distribution  of  temper- 
ature in  the  United  States ;  335-354,  Geographical  distribution  of 
rainfall  and  humidity ;  355-363,  Geographical  distribution  of  winds 
in  the  United  States. 

31.  RELATION  OF  CLIMATE  TO  LIFE 

Text-books.  Davis,  1-7,  56.  Davis  Ele.,  349-364.  Dryer,  390. 
Gilbert  and  Brigham,  189-193,  359-366. 

Reference  books.  Moore,  Climate,  Its  Physical  Basis  and  Con- 
trolling Factors :  15-19,  Economic  aspects  of  climate. 

Shaler,  Story  of  Our  Continent :  2-6,  Relations  of  climate  to  life. 

CHAPTER  V 

THE  STRUCTURE  OF  THE  EARTH 

32.  THE  EARTH  AS  A  WHOLE 

Text-books.  Davis  Ele.,  15-17.  Dryer,  26-29.  Gilbert  and 
Brigham,  4-5.     Redway,  20-22.     Tarr,  13-19. 

Reference  books.  Davis,  Elementary  Meteorology :  9-10*,  The  geo- 
sphere,  hydrosphere,  and  atmosphere. 

Dodge,  Reader  in  Physical  Geography :  4-9,  Our  relation  to  the 
world  as  a  whole. 

Heilprin,  The  Earth  and  Its  Story:  111-116,  The  earth  in  its 
interior. 

Winchell,  Walks  and  Talks  in  the  Geological  Field:  117-124, 
Imprisoned  heat. 

Special  terms.  Sphere,  centrosphere,  lithosphere,  hydrosphere, 
atmosphere,  molten  mass,  density,  crust  of  the  earth. 

33.  THE  LAND 

EXERCISE  XXVni.    Elevations  and  Depressions  of  the  Earth's  Surface  drawn 

to  Scale 

Text-books.    Davis,  93-95.     Davis  Ele.,  129-139.     Dryer,  38-46. 

Tarr,  19^-28. 


16  PHYSICAL  GEOGRAPHY  MANUAL 

Reference  books.  Dodge,  Reader  in  Physical  Geography :  10-17, 
The  larger  features  of  the  continents. 

Heilprin,  The  EaHh  and  Its  Story:  94-99,  The  ocean  trough; 
185-188,  Physiognomy  of  continents. 

Shaler,  Outlines  of  the  EartKs  History :  82^-84,  Height,  area,  and 
distribution  of  the  land. 

Shaler,  Story  of  Our  Continent :  76-78*,  Outlines  of  North  America ; 
148-150,  The  continental  shelf  of  North  America. 

Special  terms.  Coastal  shelf,  hemisphere,  great  circle,  pole  of  great 
circle,  land  hemisphere. 

34.  SLOW  MOVEMENTS  OF  THE  EARTH'S  CRUST 

Text-books.  Davis,  95-97.  Davis  Ele.,  132.  Dryer,  46-48.  Gil- 
bert and  Brigham,  10-12.    Redway,  23-25. 

Reference  books.  Brigham,  Geographic  Influences  in  American 
History :  114^-115*,  Tilting  of  the  basin  of  the  Great  Lakes. 

Russell,  Rivers  of  North  America :  179^-180*,  Terraces  of  the 
Colorado  river  due  to  elevation  of  land. 

Shaler,  Aspects  of  the  Earth :  1-9,  Upgrowth  of  the  continents. 

Shaler,  First  Book  in  Geology :  141-145,  Slow  vertical  movements. 

Shaler,  Sea  and  Land :  169-173,  Slow  rising  and  falling  of  the 
land. 

Special  terms.  Sedimentary  rock,  stratum,  strata,  fossil,  lateral 
pressure. 

35.  CAUSES  OF  MOUNTAINS 

Text-books.  Davis  Ele.,  177-178.  Dryer,  190-193.  Redway, 
65-69.     Tarr,  93-99. 

Reference  books.  Crosby,  Common  Minerals  and  Rocks :  166-177, 
Folds ;  180-188,  Faults. 

Dodge,  Reader  in  Physical  Geography :  144-149,  Mountains. 

Fairbanks,  Western  United  States :  50-59,  Earthquakes  and  moun- 
tain building. 

Heilprin,  The  Earth  and  Its  Story:  44-49,  What  a  mountain 
teaches  ;  188-194,  Physiognomy  of  mountains  ;  202-203,  Physi- 
ognomy of  rock  masses. 


THE  STRUCTURE  OF  THE  EARTH       17 

Scaler,  First  Book  in  Geology :  107-112,  Folds. 

Shaler,  Otdlines  of  the  Earth's  History :  85-91,  Causes  and  char- 
acteristics of  mountains. 

Tarr,  Elementary  Geology :  324-328,  Wrinkling  of  the  earth's 
crust,  contraction  theory. 

Winchell,  Walks  and  Talks  in  the  Geological  Field:  139-145, 
How  the  mountain  framework  is  reared. 

Special  terms.  Lateral  pressure,  weight  of  sediment,  fold,  anti- 
cline, syncline,  fault,  degradation,  erosion. 


36.  KINDS  OF  MOUNTAINS 

Text-books.  Davis,  161-171.  Davis  Ele.,  178-185.  Dryer,  178- 
179,  181-183.     Gilbert  and  Brigham,  174-181.     Tarr,  100-101. 

Reference  books.  Brigham,  Geographic  Influences  in  American 
History :  257-259,  268-272,  The  Rocky  mountains ;  287-289,  The 
mountains  of  the  Pacific  coast. 

Dodge,  Reader  in  Physical  Geography:  149-150,  Kindls  of 
mountains. 

Muir,  Mountains  of  California:  Chapter  I,  General  description 
of  the  Sierra  Nevada. 

Russell,  North  America :  74-82,  The  Appalachian  mountains ; 
122-131,  The  Rocky  mountains ;  147-158,  The  Sierra  Nevada  and 
Cascade  mountains. 

Special  terms.  Folded  mountains,  mountains  by  faulting,  block 
mountains. 

37.  LIFE  HISTORY  OF  MOUNTAINS 

Text-books.  Davis,  172-175, 187-197.  Davis  Ele.,  185-188,  204- 
212.  Dryer,  183-190.  Gilbert  and  Brigham,  182-185.  Redway, 
69-70.     Tarr,  101-103. 

Reference  books.  Dodge,  Reader  in  Physical  Geography :  160-153, 
Aging  of  mountains. 

Special  terms.    Dissection,  relict,  subdued,  monadnock. 


18  PHYSICAL  GEOGRAPHY  MANUAL 

38.  ECONOMIC  ASPECTS  OF  MOUNTAINS 

Text-books.  Davis,  175-178,  184-186.  Davis  Ele.,  188-191,  204, 
357-359.  Gilbert  and  Brigham,  188-195.  Redway,  72-75.  Tarr, 
105-109. 

Special  terms.    Tree  line,  snow  line,  barrier,  pass,  sentinel. 

39.  COASTAL  PLAINS 

Text-books.  Davis,  117-136.  Davis  Ele.,  141-158.  Gilbert  and 
Brigham,  151-155.     Tarr,  72-76. 

Reference  books.  Brigham,  Geographic  Influences  in  American 
History:  70-75,  The  Atlantic  coastal  plain;  173-180,  The  Atlantic 
coastal  plain  from  Virginia  to  Florida. 

Rnssell,  North  America:  62-73,  Coastal  plains  of  North  America ; 
94-99,  The  Gulf  plains. 

40.  PLAINS  AND  PLATEAUS 

Text-books.  Davis,  139-150.  Davis  Ele.,  158-170.  Gilbert  and 
Brigham,  155-167.     Redway,  56-65.     Tarr,  76-85. 

Reference  books.  Brigham,  Geographic  Influences  in  American 
History :  148-155,  Description  of  the  prairies ;  230-239,  The  Great 
Plains. 

Dodge,  Reader  in  Physical  Geography:  137-143,  Plains  and 
plateaus. 

Heilprin,  The  Earth  and  Its  Story:  194-196,  Physiognomy  of 
plateaus. 

Russell,  North  America:  250-253,  Prairies,  treeless  plains,  and 
plateaus. 

Shaler,  Story  of  Our  Continent:  121-123,  Prairies  of  North 
America. 

Special  terms.  Plain,  plateau,  base  level  of  erosion,  coastal  plain, 
lacustrine  plain,  alluvial  plain. 


DISINTEGRATION  AND  EROSION  19 

41.  REPRESENTATION  OF  RELIEF 
EXERCISE  XXIX.  Contoar  Lines.      XXX.  Contour  Maps 

Text-books.  Davis,  393-397.  Dryer,  48-53.  Gilbert  and  Brig- 
ham,  14-16.     Tarr,  428-430. 

Reference  books.  Brigham,  Geographic  Influences  in  American 
Historii:  332-338,  The  work  of  the  U.S.  Geological  Survey. 

Topographic  Atlas  of  the  U.S.  Geological  Survey,  Folios  1  and  2 : 
1,  Introduction  and  Topographic  map. 

Topographic  maps  of  U.S.  Geological  Survey :  Printed  matter 
on  back  of  map. 

Special  terms.    Hachures,  contour,  profile. 


CHAPTER  VI 

DISINTEGRATION  AND  EROSION 

42.  DISINTEGRATION  OF  ROCK 

EXERCISE  XXXI.    The  Weathering  of  Rocks 

Text-books.  Davis,  99-105,  265-268.  Davis  Ele.,  134-138. 
Dryer,  58-60.     Tarr,  38-42. 

Reference  books.  Dodge,  Reader  in  Physical  Geography :  69-73, 
Weathering;  120-121,  Effects  of  cold  and  frost  on  rocks. 

Jordan,  Science  Sketches :  232-255,  An  ascent  of  the  Matterhorn. 

Russell,  Rivers  of  North  America :  2-3,  Mechanical  disintegra- 
tion ;  236-240,  Vegetation  hastens  weathering. 

Shaler,  First  Book  in  Geology :  3''-4,  Frost  as  a  weathering  agent ; 
21^^-23,  Oxygen,  acids,  worms,  roots  as  weathering  agents. 

Special  terms.    Disintegrate,  oxidize. 

43.  RESIDUAL  SOIL,  CREEP,  TALUS 

Text-books.  Davis,  268-275.  Davis  Ele.,  163-164,  196-197. 
Dryer,  168.     Tarr,  42-46. 


20  PHYSICAL  GEOGRAPHY  MANUAL 

Reference  books.  Russell,  Rivers  of  North  America:  13-16*,  How 
rivers  obtain  their  loads. 

Shaler,  Outlines  of  the  Earth's  History :  322*,  Residual  soil. 
Special  terms.    Mantle  rock,  residual  soil,  creep,  talus. 

44.  THE  LOAD  OF  A  STREAM 
EXERCISE  XXXn.    The  Assorting  Power  of  Water 

Text-books.  Dryer,  61-65.  Gilbert  and  Brighara,  31-35.  Redway, 
107-109.    Tarr,  50-52. 

Reference  books.  Crosby,  Common  Minerals  and  Rocks:  19-23, 
Deposition. 

Russell,  Rivers  of  North  America:  20-22,  Transportation  of  mate- 
rial ;  240-244,  Driftwood. 

Staler,  Aspects  of  the  Earth :  146-151,  Velocity  as  related  to  car- 
rying power. 

Shaler,  First  Book  in  Geology:  20-21,  Assorting  power  of  run- 
ning water. 

Tarr,  Elementary  Geology :  174-175,  Transportation  of  sediment. 

Winchell,  Walks  and  Talks  in  the  Geological  Field :  51-52,  Trans- 
porting and  assorting  power  of  running  water  ;  57-60,  Source  and 
journey  of  sediments. 

Special  terms.    Suspension,  velocity,  sediment,  silt. 

45.  CORRASION  AND  ABRASION 
EXERCISE  XXXni.    Examination  of  Rock  Waste 

Text-books.    Dryer,  66-67.     Tarr,  52-53. 

Reference  books.  Crosby,  Common  Minerals  and  Rocks:  14-19, 
Mechanical  erosion. 

Dodge,  Reader  in  Physical  Geography:  81-88,  Erosive  work  of 
running  water. 

Russell,  Rivers  of  North  America :  28-32,  Corrasion. 

Shaler,  First  Book  in  Geology :  1-4,  Abrasion  of  river  pebbles  ; 
12-19,  Sand. 

Special  terms.    Corrasion,  abrasion,  erosion. 


RIVERS  21 

46.  MESAS,  BUTTES,  BAD  LANDS 

Text-books.  Davis,  150-152,  219»'-221.  Davis  Ele.,  171-175. 
Dryer,  214-216.     Gilbert  and  Brigham,  89-93.     Tarr,  82-83. 

Reference  books.  Crosby,  Common  Minerals  and  Rocks :  198-200, 
Table  mountains. 


CHAPTER  VII 

RIVERS 

47.  CANYONS 

Text-books.  Davis  Ele.,  164-167.  Dryer,  84-91.  Gilbert  and 
Brigham,  28-33. 

Reference  books.  Fairbanks,  Western  United  States :  10-^8,  Grand 
Canyon  of  the  Colorado;  31-40,  Canyons  of  the  Sierra  Nevada 
mountains. 

Heilprin,  The  Earth  and  Its  Story :  53-65,  Canyons. 

Shaler,  Story  of  Our  Continent :  138-140,  Canyons. 

Tarr,  Elementary  Geology :  170-173,  The  Colorado  canyon. 

Winchell,  Walks  and  Talks  in  the  Geological  Field:  61-62, 
River  gorges. 

Special  terms.    Canyon,  gorge,  ravine,  gully,  gulch,  terrace. 

48.  WATERFALLS  AND  RAPIDS 
EXERCISE  XXXIV.    A  Waterfall 

Text-books.  Davis  Ele.,  251-256.  Dryer,  95-101.  Gilbert  and 
Brigham,  38-42.     Redway,  119-121.     Tarr,  53-54. 

Reference  books.  Dodge,  Reader  in  Physical  Geography :  96-98, 
Rapids  and  waterfalls. 

Russell,  Rivers  of  North  America :  60-63,  Migration  of  water- 
falls ;  33-34%  Potholes. 

Shaler,  Aspects  of  the  Earth :  159-165,  Waterfalls. 

Shaler,  Outlines  of  the  Earth's  History :  191-193%  Waterfalls. 

Shaler,  Story  of  Our  Continent :  136-138,  Waterfalls. 


22  PHYSICAL   GEOGKAPHY  MANUAL 

Special  terms.  Rapids,  cascades,  escarpment,  fall  rock,  dip,  migra- 
tion, pothole. 

49.  VALLEYS 

Text-books.  Davis,  239-246,  278-286.  Davis  Ele.,  196-201,  256- 
258.    Dryer,  60.    Gilbert  and  Brigham,  43-45,  57-59.    Tarr,  54-59. 

Reference  books.  Heilprin,  The  Earth  and  Its  Story :  196—199, 
Physiognomy  of  valleys. 

Russell,  Rivers  of  North  America :  62-54*,  Gradient  of  river  bed ; 
145-150,  Longitudinal  profile  of  valleys  ;  150-151,  Cross  profile  of 
valleys. 

50.  FLOOD  PLAINS 

EXERCISE  XXXV.    River  Flood  Plains 

Text-books.  Davis,  286-288.  Davis  Ele.,  258-261.  Dryer,  73-79. 
Gilbert  and  Brigham,  45-49.    Redway,  113-115.    Tarr,  61-63. 

Reference  books.  Brigham,  Geographic  Influences  in  American 
History:  180-186,  The  flood  plain  of  the  lower  Mississippi. 

Dodge,  Reader  in  Physical  Geography :  88-92,  Alluvial  plains. 

Russell,  Rivers  of  North  America:  110-116,  Flood  plains; 
116-123,  Natural  levees. 

Shaler,  Outlines  of  the  EartKs  History :  186-187*,  River  flood 
plains. 

Tarr,  Elementary  Geology :  178-179,  Flood  plains. 

Special  terms.  Flood,  overflow,  levee,  crevasse,  back  swamp,  bayou, 
flood  plain. 

51.  TERRACES 

Text-books.  Davis,  280.  Davis  Ele.,  199-200.  Dryer,  160-161. 
Gilbert  and  Brigham,  52-54.    Redway,  115.    Tarr,  63-64. 

Reference  books.  Heilprin,  The  Earth  and  Its  Story :  59-60,  River 
terraces. 

Russell,  Rivers  of  North  America:  179''-183,  Terraces  of  the 
Colorado  river  and  the  Columbia. 

Tarr,  Elementary  Geology:  180,  Terraces. 

Winchell,  Walks  and  Talks  in  the  Geological  Field:  50-51, 
River  terraces. 


RIVERS  23 

52.  MEANDERS,  OXBOWS,  LAGOONS 
EXERCISE  XXXVI.    Meanders 

Text-books.  Davis,  241-246.  Davis  Ele.,  261-265.  Dryer,  75-76, 
158.    Gilbert  and  Brigham,  49-52.    Redway,  109-110.  Tarr,  62-63. 

Reference  books.  Russell,  Rivers  of  North  America :  36-38,  Meander- 
ing streams. 

Shaler,  Aspects  of  the  Earth :  152-155*,  Oxbows,  or  moats. 

Shaler,  Outlines  of  the  Earth's  History:  180^-183,  Meanders, 
oxbows. 

Special  terms.  Graded,  sediment,  deposit,  velocity,  meander,  ox- 
bow, lagoon. 

53.  DELTAS,  FANS,  CONES 

EXERCISE  XXXVn.    Alluvial  Cones 

Text-books.  Davis,  275-278,  288-296.  Davis  Ele.,  196-199, 
265-269.  Dryer,  78.  Gilbert  and  Brigham,  42-43,  54-57.  Redway, 
115-119.     Tarr,  64-67. 

Reference  books.  Dodge,  Reader  in  Physical  Geography :  92—96, 
Alluvial  fans  and  deltas. 

Russell,  Rivers  of  North  America :  101-109,  Alluvial  cones  and 
fans ;  123-125,  Deltas ;  125-127%  Deltas  of  high-grade  streams ; 
130-132,  Deltas  of  low-grade  streams. 

Shaler,  Sea  and  Land:  162°-166,  Deltas. 

Tarr,  Elementary  Geology:  176-177,  Alluvial  fans;  180-186, 
Deltas. 

Winchell,  Walks  and  Talks  in  the  Geological  Field :  54-56,  River 
sediments. 

Special  terms.    Delta,  fan,  cone,  distributary,  estuary,  bayou. 

54.  LIFE  HISTORY  OF  A  RIVER 

EXERCISE   XXXVm.    A   Region   in   Youth.      XXXIX.    A   Region   in    Maturity. 
XL.    A  Region  in  Old  Age.      XLI.    The  Life  History  of  a  River 

Text-books.  Davis,  231-233,  237-239,  251-252.  Davis  Ele.,  246- 
250,  254-255,  269-270,  270-273.  Dryer,  152-166.  Gilbert  and 
Brigham,  57-60.     Redway,  110-112. 


24  PHYSICAL  GEOGRAPHY  MANUAL 

Reference  books.  Dodge,  Reader  in  Physical  Geography :  98-99, 
Results  of  the  work  of  running  water. 

Fairbanks,  Western  United  States:  124-132,  The  Skagit  river. 

Heilprin,  The  Earth  and  Its  Story :  53,  Base  level  of  erosion. 

Russell,  Rivers  of  North  America :  46"-49^,  Base  level  of  erosion ; 
300-310,  Life  history  of  a  river ;  311-320,  Completion  of  geograph- 
ical cycle. 

55.  RIVER  SYSTEMS 
EXERCISE  XLII.    The  Drainage  Areas  of  the  United  States 

Text-books.  Davis,  230.  Davis  Ele.,  241-243.  Dryer,  61,  79-80. 
Gilbert  and  Brigham,  36,  59. 

Reference  books.  Winchell,  Walks  and  Talks  in  the  Geological 
Field :  60-61,  Drainage  areas. 

Special  terms.  River,  tributary,  river  system,  basin,  divide, 
J)ortage. 

56.  MIGRATION  OF  DIVIDES 

EXERCISE  XLIII.    The  Migration  of  Divides 

Text-books.  Davis,  246-250.  Dryer,  157-158.  Gilbert  and 
Brigham,  65-66.     Redway,  121. 

Reference  books.  Russell,  Rivers  of  North  America:  199-205, 
Stream  conquest ;  247-253,  Migration  of  divides. 

57.  CONSEQUENT,  ANTECEDENT,  ENGRAFTED,  DROWNED 

RIVERS 

Text-books.    Davis,  258-260.    Dryer,  162.    Tarr,  103-104. 
Reference  books.     Heilprin,    The   Earth   and   Its    Story:   55-59, 
Valleys,  water  gaps. 

Shaler,  Sea  and  Land :  167-168,  173-174,  Drowned  rivers. 

58.  TYPICAL  RIVERS 

Text-books.  Davis,  260-261.  Dryer,  68-80,  81-91,  92-101. 
Gilbert  and  Brigham,  66-73.  Tarr,  320-321,  322-325,  325-329, 
329-334. 


LAND  FORMS  DUE  TO  OTHER  AGENCIES  25 

Reference  books.  Fairbanks,  Western  United  States:  1-9,  The 
work  of  the  Colorado  river. 

Russell,  Rivers  of  North  America :  43-46,  Typical  rivers  —  St. 
Lawrence,  Missouri,  Colorado ;  271-275,  The  Colorado ;  275-278% 
Rivers  of  the  Sierra  Nevada  ;  296-298,  The  Niagara. 

59.  ECONOMIC  IMPORTANCE  OF  RIVERS 

Text-books.    Dryer,  163-167.    Redway,  126.     Tarr,  105-109. 
Reference  books.     Shaler,  Aspects  of  the  Earth:   185-193,  How 
removal  of  forests  affects  rivers ;  193-196,  Rivers  and  irrigation. 


CHAPTER  VIII 

LAND  FORMS  DUE  TO  OTHER  AGENCIES 

60.  TYPICAL  VOLCANOES 

Text-books.  Davis,  201-207,  209-219.  Davis  Ele.,  216-224, 
227-233.  Dryer,  194-203.  Gilbert  and  Brigham,  196-208.  Tarr, 
112-122. 

Reference  books.  Fairbanks,  Rocks  and  Minerals:  13-17,  The  be- 
ginning of  the  earth  (Kilauea). 

Heilprin,  The  Earth  and  Its  Story :  117-120,  Vesuvius. 

Russell,  Volcanoes  of  North  America :  2-7,  Stromboli ;  7-22, 
Vesuvius  ;  22-29,  Krakatoa  ;  29-36,  Hawaiian  volcanoes. 

Shaler,  Aspects  of  the  Earth:  46-56,  Pliny's  account  of  the  great 
eruption  of  Vesuvius ;  62-64,  Looking  into  the  crater  of  Vesuvius ; 
74-76,  The  eruption  of  Krakatoa. 

Shaler,  Outlines  of  the  Earth's  History :  263-266*,  A  near  view 
of  the  crater  of  Vesuvius  in  eruption  ;  276''-282,  Eruptions  of  Vesu- 
vius from  63  a.d.  to  1872 ;  289^-297*,  ^Etna ;  298''-300,  Krakatoa. 

Winchell,  Walks  and  Talks  in  the  Geological  Field:  103-111, 
Among  the  volcanoes. 


26  PHYSICAL  GEOGRAPHY  MANUAL 


61.  VOLCANIC  PHENOMENA 

EXERCISE   XLIV.    Specific   Gravity.      XLV.    Volcanic   Rocks.      XLVI.    Volcanic 
Peaks,  Plateaus,  and  Necks.     XLVn.    A  Crater 

Text-books.    Davis,  199-201,  208-209.    Davis  Ele.,  215-216,  226- 

227.  Dryer,  203-209.  Gilbert  and  Brigliam,  208-219.  Redway, 
80-90.    Tarr,  122-130. 

Reference  books.  Crosby,  Common  Minerals  and  Hocks :  109-110, 
Eruptive  rocks ;  114^-122,  Volcanic  rocks ;  148-156,  Dikes,  intru- 
sive beds,  volcanic  necks,  etc. 

Dodge,  Header  in  Physical  Geography :  154-162,  Volcanoes. 

Fairbanks,  Rocks  and  Minerals:  59-62,  The  story  of  volcanic 
rocks  ;  63-66,  Different  kinds  of  volcanic  rocks, 

Fairbanks,  Western  United  States:  19-30,  How  the  Columbia 
plateau  was  made ;  60-69,  Latest  volcanic  eruptions  in  the  United 
States ;  70—74,  Mud  volcanoes  of  the  Colorado  desert. 

Heilprin,  The  Earth  and  Its  Story :  120-127,  Volcanic  phenomena ; 
127-132,  Causes  and  distribution  of  volcanoes. 

Muir,  Mountains  of  California :  11,  Most  recent  eruption  in  the 
Sierras. 

Russell,  Lakes  of  North  America :  20-21,  Crater  lake. 

Russell,  Volcanoes  of  North  America :  193-198,  Mt.  Taylor  ;  225- 

228,  Mt.  Shasta,  California;  235-236,  Crater  lake,  Oregon;  241- 
245,  Mt.  Rainier ;  250-257,  Columbia  lava  flow ;  96-103,  Dikes, 
sheets,  plugs ;  83-90,  Structure  of  volcanic  mountains ;  208-217, 
Mono  lake,  California;  228-233,  Cinder  cone  and  lava  field  near 
Lassen's  peak,  California. 

Shaler,  Aspects  of  the  Earth:  77-89,  Distribution  and  cause  of 
volcanoes;  89<'-92,  The  craters  of  the  moon;  92-97,  Economic 
aspects  of  volcanoes. 

Shaler,  First  Book  in  Geology :  88-97,  Volcanoes. 

Shaler,  Outlines  of  the  Earth'' s  History:  303-304,  Lava  sheets; 
305-309,  Dikes ;  266-271,  Causes  of  volcanoes  ;  288-289%  309^-312, 
Economic  aspects  of  volcanoes. 

Tarr,  Elementary  Geology:  329-352,  Volcanoes. 

Winchell,  Walks  and  Talks  in  the  Geological  Field:  111-117, 
Frozen  seas  of  lava. 


LAND  FORMS  DUE  TO  OTHER  AGENCIES    27 

Special  terms.  Crater,  cinder  cone,  lava,  lava  flow,  scoria,  pumice, 
volcanic  neck,  dike. 

62.  EARTHQUAKES 

Text-books.  Davis,  183-184.  Davis  Ele.,  201-204.  Dryer,  190- 
191.  Gilbert  and  Brigham,  220-222.  Redway,  95-100.  Tarr,  130- 
132. 

Reference  books.  Dodge,  Reader  in  Physical  Geography :  163-164, 
Earthquakes. 

Heilprin,  The  Earth  and  Its  Story :  132-137,  Earthquakes. 

Shaler,  Aspects  of  the  Earth :  13-17,  Causes  of  earthquakes  ;  27- 
39,  Earthquakes  in  the  United  States  ;  39-42,  Construction  of  build- 
ings to  withstand  earthquakes ;  42^5,  Earthquake  waves  at  sea. 

Shaler,  First  Book  in  Geology :  130-140,  Earthquakes. 

Shaler,  Story  of  Our  Continent :  258-262,  Earthquakes. 

Shaler,  Outlines  of  the  Earth^s  History :  367-371,  Transmission 
of  earthquake  shocks  ;  371^-376,  Effects  of  earthquakes. 

Tarr,  Elementary  Geology:  353-361,  Earthquakes. 

Winchell,  Walks  and  Talks  in  the  Geological  Field:  125-132, 
Phenomena  and  causes  of  earthquakes. 

Special  terms.  Stress,  fault,  focus,  concentric  circles,  concentric 
spheres. 

63.  LANDSLIDES 

Text-books.  Davis  Ele.,  193-195.  Dryer,  168.  Gilbert  and 
Brigham,  105-108.    Tarr,  97. 

Reference  books.  Muir,  Mountains  of  California :  104-109,  Land- 
slide filling  a  lake ;  40,  Avalanches  of  snow. 

Shaler,  Outlines  of  the  Earth's  History:  174-177,  Landslides. 

64.  ALPINE  GLACIERS 

EXERCISE  XLVIII.    Glaciers 

Text-books.  Davis,  326-330.  Davis  Ele.,  292-294.  Dryer,  108- 
117.  Gilbert  and  Brigham,  119-128.  Redway,  153-156.  Tarr, 
137-142. 


28  PHYSICAL  GEOGKAPHY  MANUAL 

Reference  books.  Dodge,  Reader  in  Physical  Geography :  121-127, 
Glaciers  ;  127-132,  Deposits  made  by  glaciers. 

Fairbanks,  Western  United  States :  41-49,  An  Oregon  glacier. 

Heilprin,  The  Earth  and  Its  Story:  65-74,  Snow  and  glaciers; 
75-82,  The  work  of  glaciers. 

Muir,  Mountains  of  California:  15,  A  receding  glacier;  16-18, 
Magnitude  of  work  done  by  glaciers ;  26-27,  Polishing  of  rock  sur- 
face by  a  glacier ;  31-33,  A  trip  over  a  glacier  ;  81-82,  Amount  of 
work  done  by  glaciers ;  103-104,  Beginning  of  vegetation  after  gla- 
ciation ;  69,  An  imaginary  view  of  the  Sierras  in  the  Glacial  epoch. 

Russell,  Glaciers  of  North  America:  2-16,  Leading  characteristics 
of  glaciers ;  18-21,  Glacial  abrasion ;  22-28,  Glacial  deposits ; 
28-30,  Glacial  sediments ;  30-31,  Changes  in  topography  produced 
by  glaciers ;  55-62,  The  glaciers  of  Mt.  Shasta ;  62-67,  The  glaciers 
of  Mt.  Rainier;  67-69,  The  glaciers  of  Mt.  Hood;  190-205,  The 
life  history  of  a  glacier. 

Shaler,  First  Book  in  Geology :  8-12,  Glacial  pebbles. 

Shaler,  Outlines  of  the  EartKs  History :  211^^-212,  An  avalanche 
in  the  Alps ;  213-215%  The  neve ;  215^-216%  The  glacier  proper ; 
216*^-218*,  Debris  carried  by  a  glacier ;  218-221,  Crevasse,  moulin, 
esker ;  221^-223%  "  Milky  "  water  in  glacial  streams. 

Tarr,  Elementary  Geology:  195-219,  Glaciers. 

Winchell,  Walks  and  Talks  in  the  Geological  Field :  24-32,  Among 
the  glaciers. 

Special  terms.  Neve,  crevasse,  moraine,  ground  moraine,  lateral 
moraine,  terminal  moraine,  striae,  cirque,  alpine  glacier,  mountain 
glacier,  valley  glacier. 

65.  PIEDMONT  AND  CONTINENTAL  GLACIERS 

Text-books.  Davis,  324-326,  330-333.  Davis  Ele.,  290-292,  294- 
295.  Dryer,  117-121.  Gilbert  and  Brigham,  128-132.  Redway, 
156-158.    Tarr,  143-147. 

Reference  books.  Russell,  Glaciers  of  North  America :  80-91,  Muir 
glacier ;  109-127,  Malaspina  glacier ;  131-145,  Glaciers  in  the  Green- 
land region. 

Shaler,  Outlines  of  the  EaHKs  History:  225^-228%  Continental 
glaciers. 


LAND  FORMS  DUE  TO  OTHER  AGENCIES  29 

Muir,  Mountains  of  California :  Chapter  II,  The  glaciers. 
Special  terms.    Piedmont    glacier,    continental    glacier,    medial 
moraine. 

66.  THE  WORK  OF  ANCIENT  GLACIERS 
EXERCISE  XLIX.    Topographic  Fonns  due  to  Glaciation 

Text-books.  Davis,  333-346.  Davis  Ele.,  295-302.  Dryer,  122- 
134.  Gilbert  and  Brigham,  132-144,  144-150.  Redway,  158-162. 
Tarr,  148-156. 

Reference  books.  Brigham,  Geographic  Influences  in  American 
History :  41^-45,  Changes  wrought  by  ancient  glaciers  in  New  Eng- 
land; 115-126,  The  Great  Lakes  during  and  since  Glacial  times. 

Dodge,  Reader  in  Physical  Geography :  132-135,  The  work  of  the 
great  ice  sheet. 

Heilprin,  The  Earth  and  Its  Story :  82-86,  The  great  Ice  Age. 

Shaler,  Story  of  Our  Continent :  64*=-69*,  The  advance  and  extent 
of  the  ancient  ice  sheet ;  69-72*,  The  retreat  and  the  effects  of  the 
great  glacier ;  72-75,  Organic  life  during  the  glacial  period. 

Winchell,  Walks  and  Talks  in  the  Geological  Field :  11-17,  Lost 
rocks,  bowlders ;  17-24,  Arrangement  of  the  drift ;  45-50,  The 
floods  of  the  Great  Lakes. 

Special  terms.    Kettle  hole,  drift,  loess,  till,  kame,  drumlin,  erratic. 

67.  DESERTS 

Text-books.    Davis  Ele.,  280-283.   Redway,  296-298.   Tarr,  86-«9. 

Reference  books.  Brigham,  Geographic  Influences  in  American 
History:  245-251,  The  Great  Basin  and  the  arid  regions  of  the 
southwest ;  251-254,  The  civilization  of  desert  countries. 

Fairbanks,  Western  United  States :  187-197,  The  life  of  the  desert. 

Heilprin,  The  Earth  and  Its  Story:  17-18,  Desert  sands  and 
deserts. 

Shaler,  Outlines  of  the  EartKs  History:  340^-341,  Arid  regions. 

68.  SAND  DUNES 

Text-books.  Davis,  314-319.  Davis  Ele.,  286-289.  Gilbert  and 
Brigham,  109-118.    Redway,  224-227.    Tarr,  87-88. 


30  PHYSICAL  GEOGRAPHY  MANUAL 

Reference  books.  Dodge,  Reader  in  Physical  Geography:  76-80, 
The  wind. 

Roth,  First  Book  of  Forestry :  198-202,  Sand  dunes  checked  by- 
forests. 

Shaler,  First  Book  in  Geology :  17-18,  Dunes. 

Shaler,  Sea  and  Land :  49-52,  Dunes  of  sea  sand. 

Tarr,  Elementary  Geology :  129-138,  Wind  erosion. 

Westgate,  Reclamation  of  Cape  Cod  Sand  Dunes:  9-17,  Causes 
and  development  of  sand  dunes ;  18-20,  Devastation  of  the  estab- 
lished dune  areas  ;  21-34,  Artificial  reclamation  of  Cape  Cod  sands ; 
34-35,  The  Province  lands ;  38  ff.,  Plates  and  description. 

Special  terms.    Sand  blast,  dune,  migration. 

69.  CORAL  REEFS 

Text-books.  Davis,  374-383.  Davis  Ele.,  324-330.  Dryer,  174- 
177.    Gilbert  and  Brigham,  283-286.    Tarr,  217-219. 

Reference  books.  Heilprin,  The  Earth  and  Its  Story:  138-149, 
Corals  and  coral  islands. 

Jordan,  Science  Sketches :  224-228,  The  life  of  the  coral  polyp. 

Shaler,  Sea  and  Land :  86^-87,  203-207,  Coral  reefs ;  207''-209, 
Atolls. 

Shaler,  Story  of  Our  Continent :  150-152,  Coral  reefs. 


CHAPTER  IX 

IMPERFECT  DRAINAGE 

70.  LAKES,  SWAMPS,  MARSHES 

EXERCISE  L.    Lakes 

Text-books.  Davis,  232-234.  Davis  Ele.,  248-250.  Dryer,  150- 
151.  Gilbert  and  Brigham,  60-62.  Redway,  165-169,  177-183. 
Tarr,  160-170. 

Reference  books.  Brigham,  Geographic  Influences  in  American 
History:  115,  Depth  of  the  Great  Lakes. 


IMPERFECT  DRAINAGE  31 

Dodge,  Reader  in  Physical  Geography :  113-118,  Lakes. 

Fairbanks,  Western  United  States:  133-140,  The  story  of  Lake 
Clielan. 

Heilprin,  The  Earth  and  Its  Story:  60-62,  Lake  basins  and 
meadow  lands. 

Muir,  Mountains  of  California :  104-108,  Death  of  a  lake. 

Russell,  Lakes  of  North  America :  90-95,  Life  history  of  lakes. 

Shaler,  First  Book  in  Geology :  125-129,  Lakes. 

Shaler,  Outlines  of  the  Earth's  History :  198-206,  Lakes  ;  331-335, 
Bogs ;  335"-340,  Marine  marshes. 

Tarr,  Elementary  Geology:  188-194,  Destruction  of  lakes. 

Winchell,  Walks  and  Talks  in  the  Geological  Field :  52^-54,  The 
filling  of  ponds. 

71.  INTERIOR  BASINS  AND  SALT  LAKES 

Text-books.  Davis,  304-314.  Davis  Ele.,  283-285.  Dryer,  135- 
149.  Gilbert  and  Brigham,  158-160.  Redway,  169-170.  Tarr, 
163-164. 

Reference  books.  Fairbanks,  Western  United  States:  95-105,  The 
Great  Basin  and  its  peculiar  lakes;  115-123,  The  story  of  Great 
Salt  Lake. 

Russell,  North  America:  136-146,  The  Great  Basin. 

Shaler,  Story  of  Our  Continent :  212-213,  Mineral  substances  in 
sea  water. 

72.  EXTINCT  LAKES 
EXERCISE  LI.    Extinct  Lakes 

Text-books.  Davis  Ele.,  288-290.  Gilbert  and  Brigham,  155-160. 
Redway,  170-177.    Tarr,  164-165. 

Reference  books.  Fairbanks,  Western  United  States :  168-176,  Death 
valley. 

Heilprin,  The  Earth  and  Its  Story :  62-64,  Ancient  lake  basins. 

Shaler,  Story  of  Our  Continent :  146-148,  Dead  seas. 


32  PHYSICAL  GEOGRAPHY  MANUAL 

CHAPTER  X 
UNDERGROUND  WATERS 

73.  PERCOLATING  WATERS 

Text-books.  Davis,  224-225.  Davis  Ele.,  234-235.  Gilbert  and 
Brigham,  104-105.    Redway,  132-134,  139-142.      Tarr,  39-40. 

Reference  books.  Tarr,  Elementary  Geology:  150,  Underground 
waters. 

Special  terms.  Run-off,  percolate,  vegetable  mold,  impervious 
strata. 

74.  CAVERNS 
EXERCISE  Ln.    Solids  in  Solution 

Text-books.    Davis,  225-226.    Davis  Ele.,  235-236.    Dryer,  104- 

105.  Gilbert  and  Brigham,  98-100.    Tarr,  59-60. 

Reference  books.  Muir,  Mountains  of  California :  329-330,  Caves 
of  the  mountains  of  California ;  333-337,  A  visit  to  a  cave. 

Shaler,  Aspects  of  the  Earth :  98-115,  Caverns  and  natural  bridges. 

Shaler,  First  Book  in  Geology :  74-87,  The  course  of  water  under- 
ground. 

Shaler,  Outlines  of  the  Earth'' s  History:  250-251,  Dissolving 
power  of  water  having  carbon  dioxide  in  it ;  253-255,  Caverns ; 
255^-256,  Stalactites  ;  256*'-258,  Natural  bridges. 

Shaler,  Story  of  Our  Continent :  140-145,  Caverns. 

Tarr,  Elementary  Geology :  140-143,  Caves. 

Special  terms.  Solid,  solvent,  solution,  saturated  solution,  sedi- 
ment, evaporation,  stalactite,  stalagmite. 

75.  SPRINGS 

Text-books.    Davis,  226-229.    Davis  Ele.,  236-239.    Dryer,  105- 

106.  Gilbert  and  Brigham,  100-103.    Redway,  135-136. 
Reference  books.    Dodge,  Reader  in  Physical  Geography :  206-212, 

Springs  and  wells. 

Heilprin,  The  Earth  and  Its  Story :  87,  Mineral  waters ;  91-93, 
Hot  springs  and  geysers. 


UNDERGROUND  WATERS  33 

Shaler,  Aspects  of  the  Earth :  123-130,  Caverns  formed  by  hot 
springs, 

Shaler,  Story  of  Our  Continent :  253-258,  Underground  water. 

Tarr,  Economic  Geology  of  the  United  States :  418-420,  Mineral 
waters. 

Tarr,  Elementary  Geology :  145—147,  Springs. 

Winchell,  Walks  and  Talks  in  the  Geological  Field :  32-38,  The 
hillside  spring  and  its  work. 

76.  ARTESIAN  WELLS 

Text-books.  Davis,  126-127.  Davis  Ele.,  238.  Dryer,  102-103. 
Gilbert  and  Brigham,  103-104.    Redway,  135.    Tarr,  72'>-73. 

Reference  books.  Shaler,  Outlines  of  the  Earth's  History :  258^-259, 
Artesian  wells. 

Tarr,  Economic  Geology  of  the  United  States :  412-418,  Artesian 
wells. 

Tarr,  Elementary  Geology :  147-149,  Artesian  wells. 

77.  GEYSERS 

Text-books.  Davis,  229-230.  Davis  Ele.,  239-241.  Dryer,  106. 
Gilbert  and  Brigham,  103.     Redway,  136-138.     Tarr,  132-133. 

Reference  books.  Dodge,  Header  in  Physical  Geography :  164, 
Geysers  and  hot  springs. 

Jordan,  Science  Sketches :  256-263,  The  formation  of  geysers. 

Tarr,  Elementary  Geology:  362-365,  Geysers. 

Winchell,  Walks  and  Talks  in  the  Geological  Field:  93-102, 
A  walk  in  the  Yellowstone  park. 

78.  VEINS 
EXERCISE  Lin.    Veins 

Reference  books.  Crosby,  Common  Minerals  and  Rocks :  123—126, 
Vein  rocks ;  156''-165,  The  structure  of  veins. 

Fairbanks,  Rocks  and  Minerals :  67-70,  The  story  of  a  piece  of 
quartz ;  71-75,  Some  varieties  of  quartz. 


34  PHYSICAL  GEOGRAPHY  MANUAL 

Shaler,  First  Book  in  Geology :  66-73,  Veins. 
Shaler,  Outlines  of  the  EartKs  History :  259*'-261,  Mineral  veins. 
Shaler,  Story  of  Our  Continent:  213-214,  Method  of  formation 
of  veins. 


CHAPTER  XI 
THE  OCEAN 

79.  SOUNDINGS 

Text-books.  Davis,  61-62.  Davis  Ele.,  98-99.  Gilbert  and 
Brigham,  298-299.     Tarr,  173-174. 

Reference  books.     Shaler,  Sea  and  Land :  75-80,  Soundings. 
Special  terms.    Fathom,  dredge,  self-registering  thermometer. 

80.  THE  SEA  BOTTOM 

Text-books.  Davis,  67-71.  Davis  Ele.,  105-109.  Dryer,  243-249. 
Gilbert  and  Brigham,  279-282.    Tarr,  175-178. 

Reference  books.  Brigham,  Geographic  Influences  in  American 
History:  350°-354,  The  work  of  the  U.S.  Coast  Survey  and  the 
Hydrographic  Office. 

Shaler,  Sea  and  Land:  80''-86%  The  shape  of  the  sea  floor;  105, 
Ooze ;  108-114,  The  fate  of  human  bodies,  ships,  etc.,  buried  at  sea. 

Winchell,  Walks  and  Talks  in  the  Geological  Field :  64-70,  The 
sea  bottom. 

Special  terms.  Ooze,  calcareous,  mud,  red  clay,  continental  shelf, 
deeps. 

81.  OCEAN  WATER 
EXERCISE  LIV.    The  Density  and  Temperature  of  Sea  Water 

Text-books.  Davis,  62-65.  Davis  Ele.,  100-102.  Dryer,  250-255. 
Gilbert  and  Brigham,  286-288.  Redway,  190-192.    Tarr,  179-184. 

Reference  books.  Shaler,  Sea  and  Land:  106,  The  cause  of  the 
cold  of  the  deep  sea. 

Special  terms.    Density,  solution,  salt. 


THE  OCEAN  35 

82.  WAVES 

Text-books.  Davis,  71-76.  Davis  Ele.,  109-114.  Dryer,  258-260. 
Gilbert  and  Brigham,  288-290.    Redway,  194-196.    Tarr,  184-187. 

Reference  books.  Dodge,  Reader  in  Physical  Geography :  100-105, 
Wave  erosion. 

Shaler,  Outlines  of  the  EartKs  History :  132-138*,  Waves. 

Tarr,  Elementary  Geology:  221-231,  Waves. 

Special  terms.    Trough,  crest,  white  cap,  breaker,  surf,  undertow. 

83.  TIDES 

EXERCISE  LV.    Tides 

Text-books.  Davis,  83-88.  Davis  Ele.,  119-122.  Dryer,  260-264. 
Gilbert  and  Brigham,  290-293.    Redway,  197-200.    Tarr,  187-190. 

Reference  books.  Dodge,  Reader  in  Physical  Geography :  111-113, 
Tides. 

Xewcomb,  Elements  of  Astronomy :  121-123,  Tides. 

Shaler,  First  Book  in  Geology :  122-124,  Physiographic  effects  of 
tides. 

Shaler,  Outlines  of  the  Earth's  History:  126''-132,  Tides. 

Shaler,  Sea  and  Land:  21P-213*,  Tides;  223-229,  Effects  of 
tides  on  harbors. 

Tarr,  Elementary  Geology:  231-234,  Tides. 

Young,  Lessons  in  Astronomy :  181-187,  Tides. 

Special  terms.  Gravitation,  centrifugal  force,  high  tide,  low  tide, 
slack  water,  spring  tide,  neap  tide,  ebb,  flow,  range  of  tide,  bore. 

84.  OCEAN  CURRENTS 
EXERCISE  LVI.    Ocean  Corrents 

Text-books.  Davis,  77-83.  Davis  Ele.,  114-11 9.  Dryer,  264-270. 
Gilbert  and  Brigham,  294-297.    Redway,  200-205.    Tarr,  190-194. 

Reference  books.  Dodge,  Reader  in  Physical  Geography :  108-111, 
Ocean  currents. 

Shaler,  First  Book  in  Geology :  102-106,  Ocean  currents. 


36  PHYSICAL  GEOGRAPHY  MANUAL 

Shaler,  Outlines  of  the  Earth'' s  History :  145-148,  The  cause  of 
ocean  currents ;  148-150,  The  Gulf  stream ;  150-152,  The  cold 
currents ;  152-156,  Climatic  and  other  influences  of  ocean  currents. 

Tarr,  Elementary  Geology :  235-237,  Ocean  currents. 

Special  terms.  Eddy,  drift,  stream,  sargasso  sea,  equatorial  current. 

85.  ICEBERGS,  FLOES,  PACKS 
EXERCISE  LVn.    Icebergs 

Text-books.  Davis,  65-67.  Davis  Ele.,  102-104.  Dryer,  270-271. 
Gilbert  and  Brigham,  297-298.    Redway,  162.    Tarr,  194-195. 

Reference  books.  Russell,  Glaciers  of  North  America :  83-86,  Ice- 
bergs. 

Shaler,  Outlines  of  the  EaHh's  History :  242''-243,  Icebergs. 

Shaler,  Sea  and  Land:  115-123,  Formation  of  ice  floes  ;  123-132, 
Formation  of  icebergs ;  133-139,  Death  of  icebergs ;  139-145, 
Climatic  and  physiographic  effects  of  icebergs ;  146-149,  Beauty 
of  icebergs ;  148-152,  Perils  due  to  icebergs. 

Special  terms.    Specific  gravity,  glacier,  iceberg,  floe,  pack. 

86.  THE  SEA  AND  MAN 

EXERCISE  LVin.    The  Sea  and  Man 

Text-books.  Davis,  57-59,  73.  Davis  Ele.,  97,  110-111.  Dryer, 
271-272.    Gilbert  and  Brigham,  300-301,  315-318.    Tarr,  15. 

87.  LIFE  IN  THE  OCEAN 

Text-books.  Davis,  88-90.  Davis  Ele.,  122-124.  Dryer,  379-382. 
Gilbert  and  Brigham,  299-300,  343-345.    Tarr,  195-198. 

Reference  books.  Shaler,  Sea  and  Land :  25-27,  Animal  and  vege- 
table life  along  shore ;  90-107,  Life  in  the  sea ;  229-243,  Marine 
life  (vegetable)  as  related  to  harbors ;  243-262,  Marine  life  (animal) 
as  related  to  harbors. 

Winchell,  Walks  and  Talks  in  the  Geological  Field :  69-70,  Life 
in  the  sea. 

Special  terms.  Seaweed,  coral,  calcareous,  phosphorescence,  blind- 
ness, commercial  value. 


COAST  FORMS  37 

CHAPTER  XII 

COAST  FORMS 

88.  CONTINENTAL  OUTLINES 

Text-books.  Davis,  70,  93-98.  Davis  Ele.,  129-134.  Dryer, 
38-45.    Gilbert  and  Brigham,  281.    Redway,  42-46.    Tarr,  22-28. 

Reference  books.  Russell,  North  America :  1-16,  The  continental 
shelf  of  North  America  ;  32^0,  Changes  in  the  coast  line  of  North 
America  due  to  waves  and  currents  ;  40-50,  Changes  due  to  oscilla- 
tion of  the  land. 

Shaler,  Sm  and  Land :  62-66,  87«-89',  Continental  shelf. 

89.  ISLANDS 

Text-books.  Davis,  374-383.  Davis  Ele.,  324-330.  Dryer,  45, 
174-177.  Gilbert  and  Brigham,  282-286.  Redway,  46-48.  Tarr, 
217-219,  222-223. 

Reference  books.  Shaler,  Chttlines  of  the  Earth's  History :  84*'-85', 
Islands. 

Shaler,  Story  of  Our  Continent:  78-81,  Islands  near  North 
America. 

Special  terms.  Continental  shelf,  continental  island,  volcanic 
island,  coral  reef,  atoll,  stack. 

90.  ENCROACHMENT  OF  SEA  ON  LAND 
EXERCISE  LIX.  Headlands,  Beaches,  Sea  Caves 

Text-books.  Davis,  360-366.  Davis  Ele.,  304-314,  314-322. 
Dryer,  229-231.    Gilbert  and  Brigham,  302-310.    Tarr,  210-212. 

Reference  books.  Dodge,  Reader  in  Physical  Geography :  100-105, 
Wave  erosion. 

Heilprin,  The  Earth  and  Its  Story :  104-106,  Wear  of  the  shore 
line. 

Shaler,  Aspects  of  the  Earth :  130-134,  Sea  caves. 

Shaler,  First  Book  in  Geology:  5-8,  Sea  pebbles;  15-19,  Sand 
on  the  seashore  ;  86-87,  Sea  caves. 


38  PHYSICAL  GEOGRAPHY  MANUAL 

Shaler,  Outlines  of  the  Earth's  History :  138''-145,  The  work  of 
the  "  sea  mill." 

Shaler,  Sea  and  Land :  8-12*,  Strong  coasts ;  15-20,  Sea  caves, 
natural  bridges,  etc. ;  27-30,  Weak  coasts ;  41*'-46,  Wearing  of 
pebbles  on  a  beach ;  48,  Beach  wall. 

Special  terms.  Strong  shore  line,  weak  shore  line,  headland,  sea 
cliff,  sea  cave,  bay,  beach,  abrasion,  bowlder,  pebble,  sand. 

91.  ENCROACHMENT  OF  LAND  ON  SEA 
EXERCISE  LX.    Barrier  Beaches 

Text-books.  Davis,  369-376.  Davis  Ele.,  322-327.  Dryer,  231- 
238.    Gilbert  and  Brigham,  310-313.    Tarr,  212-220. 

Reference  books.  Dodge,  Reader  in  Physical  Geography :  105-108) 
Wave  deposits. 

Heilprin,  The  Earth  and  Its  Story:  106^-110,  The  ocean  as  a 
receiving  basin. 

Shaler,  First  Book  in  Geology :  20-23,  Mud. 

Shaler,  Sea  and  Land :  49-52,  Dunes  of  sea  sand  ;  68-72,  Barrier 
reefs  and  sea  marshes ;  86*'-87,  Coral  reefs ;  187-197,  Sand  reefs  ; 
190''-192,  Cause  of  sand  reefs;  203-207,  Coral  reefs;  207''-209, 
Atolls ;  233-243,  Marine  marshes. 

Shaler,  Story  of  Our  Continent:  84-87,  Barrier  islands  of  the 
Atlantic  and  Gulf  coast. 

Tarr,  Elementary  Geology :  243-259,  Deposition  in  the  sea. 

Special  terms.    Hook,  spit,  reef,  bar,  dune,  delta,  stratification. 

92.  RISING  AND  SINKING  COASTS 
EXERCISE  LXI.  Drowned  and  Elevated  Coasts 

Text-books.  Davis,  357,  366-369.  Davis  Ele.,  317-322.  Dryer, 
95,  227-229.    Gilbert  and  Brigham,  313-314.    Tarr,  204-210. 

Reference  books.  Dodge,  Reader  in  Physical  Geography :  165-170, 
Movements  of  the  land. 

Fairbanks,  Western  United  States:  75-85,  History  of  a  coast  line. 

Heilprin,  The  Earth  and  Its  Story :  99-104,  Inconstancy  of  oceanic 
and  land  levels  ;  199-202,  Physiognomy  of  the  coast  line. 


MINERALS  AND  ROCKS  39 

Russell,  Rivers  of  North  America :  217-221,  Effects  of  subsidence. 

Shaler,  Outlines  of  the  EartKs  History :  91''-96,  Rising  and  sink- 
ing coasts. 

Shaler,  Sea  and  Land :  34''-37,  Rising  coasts,  old  sea  margins ; 
169-173,  Rising  and  sinking  coasts. 

Shaler,  Story  of  Our  Continent :  81-84,  Islands  and  inlets  of  north- 
eastern North  America. 

Winchell,  Walks  and  Talks  in  the  Geological  Field:  80-81,  An 
Arabian  narrative  of  rising  and  sinking  coasts. 

Special  terms.    Coastal  plain,  terrace,  drowned  lands,  fiord. 

93.  COAST  OUTLINES  AND  CIVILIZATION 

Text-books.  Davis,  196,  358-359.  Davis  Ele.,  320-322,  368. 
Gilbert  and  Brigham,  315-318.    Tarr,  203-204,  223-225. 

Reference  books.  Shaler,  Sea  and  Land :  154-161,  Coast  outlines 
and  civilization. 

94.  HARBORS 
EXERCISE  LXII.    Harbors 

Text-books.    Davis  Ele.,  120-122.    Tarr,  223-225. 
Reference  books.    Shaler,  Sea  and  Land :  161''-162,  What  makes 
a  good  harbor ;  162-186,  187-222,  223-252,  Harbors. 


CHAPTER  XIII 

MINERALS  AND  ROCKS 

95.  ECONOMIC  MINERALS  AND  ORES 

EXERCISE  LXin.    Economic  Minerals  and  Ores 

Text-books.    Tarr,  408. 

Reference  books.  Fairbanks,  Rocks  and  Minerals :  103-106,  Coal, 
graphite,  diamond ;  135-139,  Gold  ;  140-144,  Placer  mining ;  146- 
150,  Iron ;  151-153,  Copper ;  155-158,  Silver ;  159-162,  Lead  and 
zinc;   163-165,  Tin;   166-167,  Mercury  or  quicksilver;   170-171, 


40  PHYSICAL  GEOGRAPHY  MANUAL 

Platinum;  172-174,  Aluminum;  178-180,  Sulphur;  181-183, 
Gypsum;  193-194,  Garnet;  195-196,  Asbestos;  204-211,  Salt; 
212-215,  Borax  and  soda. 

Fairbanks,  Western  United  States:  215-222,  The  life  of  the 
prospector;  223-232,  Gold  and  gold  mining;  233-240,  Copper 
mining. 

Heilprin,  The  Earth  and  Its  Story:  207-209,  Gold  and  silver; 
209-213,  Copper,  zinc,  tin,  lead ;  215-220,  Iron ;  220-224,  Mercury, 
platinum,  aluminum,  sulphur ;  225,  Rock  salt ;  225-226,  Gypsum. 

Shaler,  Story  of  Our  Continent :  205-209%  Importance  of  minerals 
in  North  America ;  228-231,  Methods  of  occurrence  of  gold ; 
222-224,  Iron. 

Tarr,  Economic  Geology  of  the  United  States :  144-146,  Production 
of  iron  ore  in  the  United  States ;  224-227,  Production  of  copper  in 
the  United  States. 

Winchell,  Walks  and  Talks  in  the  Geological  Field:  145-153, 
Down  in  a  mine ;  153-159,  Iron  and  its  geology  ;  159-165,  Salt 
and  gypsum. 


96.  ORGANICALLY  FORMED  ROCKS 
EXERCISE  LXIV.    Limestone.     LXV.    Coal 

Text-books.    Davis,  102-103.    Tarr,  410-411. 

Reference  books.  Crosby,  Common  Minerals  and  Rocks :  23-30, 
Organic  agencies  in  rock  formation ;  81-94,  Chemically  and  organ- 
ically formed  rocks. 

Fairbanks,  Rocks  and  Minerals :  79—84,  How  animals  and  plants 
help  to  make  the  rocks  ;  85-86,  Diatomaceous  earth  ;  87-91,  Lime- 
stone and  marble  ;  92-96,  Calcite  and  dolomite. 

Fairbanks,  Western  United  States :  241-246,  Coal. 

Heilprin,  The  Earth  and  Its  Story :  23-26,  Limestone  and  marble; 
26-29,  Coquina,  chalk,  ooze  ;  224-225,  Graphite  ;  226-230,  Coal. 

Shaler,  First  Book  in  Geology:  38-45,  Limestone;  46-55,  Coal. 

Shaler,  Story  of  Our  Continent :  38-44,  The  coal-making  time  in 
North  America ;  209-210%  The  origin  of  coal ;  214-219,  Distribution 
of  coal  in  the  United  States. 


MINERALS  AND  ROCKS  41 

Tarr,  Economic  Geology  of  the  United  States :  311-314,  Coal ;  314- 
321,  Coal  areas  in  the  United  States ;  321-326,  Origin  of  coal ; 
326-331,  Conditions  existing  in  Carboniferous  times;  331-333, 
Uses  of  coal ;  333-336,  The  production  of  coal. 

Winchell,  Walks  and  Talks  in  the  Geological  Field:  183-189, 
Solidified  sunlight  —  coal  and  coal  beds ;  214-220,  Lone  burials  in 
the  coal  lands. 

97.  PETROLEUM  AND  NATURAL  GAS 

Reference  books.  Fairbanks,  Rocks  and  Minerals:  97-102,  The 
story  of  petroleum. 

Fairbanks,  Western  United  States :  246-248,  Petroleum. 

Heilprin,  The  Earth  and  Its  Story:  230-231,  Petroleum  and 
natural  gas. 

Slialer,  Story  of  Our  Continent:  210-211,  Petroleum  and  rock 
gas ;  219^-222*,  Distribution  of  petroleum,  oil,  and  gas  in  North 
America. 

Tarr,  Economic  Geology  in  the  United  States :  340-346,  Origin  of 
petroleum ;  346-347,  Uses  of  petroleum ;  347-349,  Production  of 
petroleum  ;  351*-355,  Natural  gas  ;  355-357,  Asphaltum, 

Winchell,  Walks  and  Tal/cs  in  the  Geological  Field :  166-172,  Liquid 
sunlight  —  petroleum ;  173-183,  Gaseous  sunlight  —  natural  gas. 

98.  FOSSILS 

Reference  books.  Crosby,  Common  Minerals  and  Rocks:  141-147, 
Ripple  marks,  fossils, 

Fairbanks,  Rocks  and  Minerals:  76-78,  How  wood  changes  to 
stone. 

Heilprin,  The  Earth  and  Its  Story:  38-39,  Fossil  imprints  in  the 
rocks ;  150-153,  Fossils. 

Shaler, First  Book  in  Geology:  189-194,  How  fossils  are  formed. 

Shaler,  Sea  and  Land:  121''-124,  Forests  silicified  while  buried 
in  sand. 

Ward,  Report  on  the  Petrified  Forests  of  Arizona :  9-10,  Scenic 
features ;  10-11,  Location  of  the  petrified  forests ;  11-17,  Geological 
considerations  ;  17-19,  Preservation  of  the  petrified  forests ;  22-23, 
Recommendations. 


42  PHYSICAL  GEOGRAPHY  MANUAL 

Winchell,  Walks  and  Talks  in  the  Geological  Field :  78-81,  Fossils ; 
189-197,  Monsters  of  a  buried  world ;  206-214,  Lessons  from  chalk. 

99.  IGNEOUS  ROCKS 
EXERCISE  LXVI.    Granite 

Text-books.  Dryer,  34-36.  Gilbert  and  Brigham,  6-7,  76-78. 
Tarr,  33-34,  406-407,  411-412. 

Reference  books.  Crosby,  Common  Minerals  and  Rocks :  111-114, 
Plutonic  or  dike  rocks. 

Fairbanks,  Bocks  and  Minerals :  27-33,  What  we  find  in  granite ; 
34-37,  How  granite  decays ;  70,  Use  of  quartz. 

Heilprin,  The  Earth  and  Its  Story :  30-32,  Granite. 

Shaler,  First  Book  in  Geology :  12-15,  Sand. 

Winchell,  Walks  and  Talks  in  the  Geological  Field :  39-44,  Kinds 
of  minerals  and  rocks. 

100.  FRAGMENTAL  ROCKS 
EXERCISE  LXVII.   Fragmental  Rocks 

Text-books.  Davis,  101-102.  Dryer,  32-34.  Gilbert  and  Brig- 
ham,  74-76.    Tarr,  409. 

Reference  books.  Crosby,  Common  Minerals  and  Bocks:  72-80, 
Fragmental  rocks ;   129-137,  Stratification ;   137-140,  Overlap,  etc. 

Fairbanks,  Bocks  and  Minerals :  47-51,  How  rocks  are  made ; 
53-55,  Three  kinds  of  sedimentary  rocks. 

Heilprin,  The  Earth  and  Its  Story :  20-23,  Sandstone  and  pebble 
rock ;  39-43,  Stratification,  folding,  dip ;  29-30,  Flags,  shales,  slates. 

Shaler,  First  Book  in  Geology :  30-33,  Conglomerate ;  34-35, 
Sandstone ;  36-37,  Mud  stones. 

Winchell,  Walks  and  Talks  in  the  Geological  Field :  44^5,  Sedi- 
mentary rocks ;  71-77,  Strata  and  their  classification. 

101.  METAMORPHIC  ROCKS 

Text-books.    Dryer,  35-36.    Tarr,  34,  413. 

Reference  books.  Crosby,  Common  Minerals  and  Bocks:  30-34, 
Igneous  agencies ;  95-108,  Metamorphic  rocks. 


WEATHERING  AND  SOILS  43 

Fairbanks,  Rocks  and  Minerals:  56-58,  Slate,  mica  schist,  and 
quartzite. 

Heilprin,  The  Earth  and  Its  Story :  33-35,  Gneiss  and  schists. 

102.  BUILDING  STONE 
EXERCISE  LXVm.    Building  Stone 

Reference  books.  Heilprin,  The  Earth  and  Its  Story:  232-238, 
Building  stone. 

Tarr,  Economic  Geology  of  the  United  States:  359-360,  What 
stones  are  used  for  building  purposes;  383-384,  Building-stone 
production  in  the  United  States. 


CHAPTER  XIV 

WEATHERING  AND  SOILS 

103.  DECOMPOSING  AGENTS 

EXERCISE  LXIX.    Decomposing  Agents 

Reference  books.  Bailey,  Principles  of  Agriculture :  16-22,  What 
soil  is  and  how  it  is  made. 

Crosby,  Common  Minerals  and  Hocks :  10'*-14,  Chemical  erosion. 

Heilprin,  The  Earth  and  Its  Story :  13-17,  The  decay  of  rocks. 

Jordan,  Science  Sketches :  232-255,  An  ascent  of  the  Matterhorn. 

Russell,  Rivers  of  North  America :  2-3,  Mechanical  disintegration  ; 
236-240,  Vegetation  hastens  weathering. 

Shaler,  Aspects  of  the  Earth:  300-309,  Agents  of  soil  formation. 

Shaler,  First  Book  in  Geology :  3''^,  Frost  as  a  weathering  agent ; 
21''-23,  Oxygen,  acids,  worms,  roots,  as  weathering  agents. 

Shaler,  Outlines  of  the  Earth's  History :  315''-321%  Effect  of  organic 
life  on  soil. 

Shaler,  Sea  and  Land :  21-26,  Weathering  agencies  along  shore. 

Tarr,  Elementary  Geology:  109-119,  Decomposing  agents;  128, 
Summary  of  weathering. 

Winslow,  Principles  of  Agriculture :  30-35,  The  soil. 


44  PHYSICAL  GEOGRAPHY  MANUAL 

104.  KINDS  OF  SOIL 

Reference  books.  Bailey,  Principles  of  Agriculture :  22-25,  Trans- 
portation of  soil. 

Dodge,  Reader  in  Physical  Geography:  73-76,  The  effects  of 
gravity  in  soil  making  ;  201-203,  Kinds  of  soil. 

Heilprin,  The  Earth  and  Its  Story :  238-240,  Clays  and  soils. 

King,  Inngation  and  Drainage:  269-274,  Alkali  lands;  280-289, 
Treatment  and  use  of  alkali  lands. 

Shaler,  Aspects  of  the  Earth:  317-329,  Kinds  of  soil  and  soil  zones. 

Shaler,  First  Book  in  Geology :  24-29,  Soils. 

Shaler,  Outlines  of  the  Earth^  s  History:  322''-327,  Transported  soil. 

Shaler,  Story  of  Our  Continent :  183-190,  Glacial,  residual,  alluvial 
soils ;  190-192,  Alkali  land. 

Tarr,  Economic  Geology  of  the  United  States :  391-394,  Residual 
or  indigenous  soils ;  394-396,  Transported  soils ;  396-398,  Glacial 
soils ;  399-402,  Clays. 

Tarr,  Elementary  Geology :  120-121,  Residual  soil  and  soil  zones. 

Winslow,  Principles  of  Agriculture :  35-39,  The  composition  of 
the  soil. 

105.  FERTILITY  OF  THE  SOIL 

Reference  books.  Bailey,  Principles  of  Agriculture :  25-36,  The 
resources  of  the  soil ;  37-46,  The  texture  of  the  soil ;  47-50,  57<=-59% 
Moisture  in  the  soil ;  50-57,  59''-63,  Increase  and  conservation  of 
moisture  in  the  soil. 

Brigham,  Geographic  Influences  in  American  History :  46^-50, 
Barren  soil  and  abandoned  farms  of  New  England. 

Dodge,  Reader  in  Physical  Geography :  198-201,  Soils ;  204-205, 
Fertility  of  soils. 

Shaler,  Aspects  of  the  EaHh :  329-339,  Fertility  of  the  soil. 

Shaler,  Outlines  of  the  Earth'' s  History :  327''-331°-,  Conditions  of 
fertility  of  soil ;  343-348,  How  cultivation  injures  soil. 

Shaler,  Story  of  Our  Continent :  6*'-9%  Fertility  of  the  soil. 

Tarr,  Economic  Geology  of  the  United  States :  398-399,  Wearing 
out  of  soils  by  cultivation. 

Winslow,  Principles  of  Agriculture :  77-80,  Fertile  soil ;  80-83, 
Elements  which  generally  fail  soonest. 


WEATHERING  AND  SOILS  45 

106.  FERTILIZERS 

Reference  books.  Bailey,  Principles  of  Agriculture :  64-76,  The 
tillage  of  the  soil. 

Heilprin,  The  Earth  and  Its  Story:  240-241,  Lime,  guano, 
phosphates. 

Moore,  Bacteria  and  the  Nitrogen  Problem :  333-342,  Bacteria  and 
the  nitrogen  problem. 

Tarr,  Economic  Geology  of  the  United  States:  402-412,  Fertilizers. 

Winslow,  Principles  of  Agriculture :  83-89,  Artificial  and  pre- 
pared fertilizers ;  89-97,  Methods  of  applying  fertilizers  ;  100-107; 
Cultivation;  108-110,  Draining;  110-112,  Rotation  of  crops. 

107.  IRRIGATION 
EXERCISE  LXX.    Irrigation 

Reference  books.  Fairbanks,  Western  United  States:  259-267, 
Irrigation. 

King,  Irrigation  and  Drainage :  66-72,  Antiquity  of  irrigation ; 
72-77,  Irrigation  in  Europe ;  77-84,  Irrigation  in  Asia ;  84-85, 
Irrigation  in  Egypt ;  88-89,  Summary  of  extent  of  irrigation ; 
239-241,  Units  of  measurement  of  water ;  290-296,  Diverting  river 
water,  Punjab,  India;  296-304,  Diverting  river  water,  Redlands, 
California;  328,  Use  of  animal  power  for  lifting  water;  338-344, 
Irrigation  by  flooding ;  352-359,  Field  irrigation  by  furrows ; 
373-381,  Orchard  irrigation ;  396-402,  Subirrigation. 

King,  The  Soil:  268-275,  Irrigation. 

Kinney,  Forest  and  Water :  189,  Measurement  of  water ;  229-233, 
Variation  in  stream  flow ;  191-198,  Methods  of  irrigation. 

Meade,  Irrigation  Institutions:  100-113,  Measurement  of  water. 

108.  FORESTRY  AS  RELATED  TO  THE  SOIL 

Reference  books.  California  Water  and  Forest  Association,  Should 
the  Forests  be  preserved?  7-13,  Forestry  and  irrigation;  18-21, 
How  forests  prevent  floods ;  22-27,  Forests  and  water  storage. 

Gifford,  Practical  Forestry :  46-61,  The  forest  as  a  soil  former ; 
51-56,  The  forest  as  a  soil  improver ;  56-58,  The  forest  as  a  soil 


46  PHYSICAL  GEOGRAPHY  MANUAL 

fixer ;  58-63,  The  forest  as  a  flood  preventer  and  a  conservator  of 
moisture. 

■  Kinney,  Forest  and  Water:  22,  Advantages  of  forested  water- 
sheds; 78-86,  Torrents;  91-97,  Control  of  torrents;  174-177, 
Forests  increase  rainfall  and  conserve  moisture ;  185-186,  Forests 
prevent  evaporation. 

Roth,  A  First  Book  of  Forestry :  203-209,  The  forest  as  a  pro- 
tective covering. 

Russell,  Rivers  of  North  America :  236-240,  Forestry. 

Shaler,  Aspects  of  the  Earth :  259-261,  Forests  enrich  the  soil ; 
270-275,  Forests  prevent  floods  and  increase  rainfall ;  290-293, 
Underground  work  of  forests. 

Tourney,  Relation  of  Forests  to  Stream  Flow:  279-288,  The  relation 
of  forests  to  stream  flow. 


CHAPTER  XV 

PLANTS,  ANIMALS,  AND  MAN 

109.    CONDITIONS   OF  LIFE 

Text-books.  Davis  Ele.,  332-337.  Dryer,  349-351.  Gilbert  and 
Brigham,  332-338.     Redway,  303-308.     Tarr,  336-339,  353-354. 

Reference  books.  Coulter,  Plant  Studies:  169-175,  The  environ- 
ment of  a  plant. 

Jordan  and  Kellogg,  Animal  Life:  106-113,  The  primary  condi- 
tions of  animal  life. 

Pinchot,  Primer  of  Forestry,  Part  I  :  7-24,  The  life  of  a  tree ; 
25-43,  Trees  in  the  forest. 

Osterhout,  Experiments  with  Plants:  326-343,  How  plants  are 
influenced  by  water ;  344-348,  How  plants  are  influenced  by  light ; 
348-349,  How  plants  are  influenced  by  wind ;  349-351,  How 
plants  are  influenced  by  food ;  352-360,  How  plants  are  influenced 
by  heat. 

Winslow,  Principles  of  Agriculture :  55-57,  Conditions  of  growth; 
61-62,  Plants  purify  the  air ;  66-68,  Food  from  soil ;  71-73,  Sap, 
nutrition,  selection. 


PLANTS,  ANIMALS,  AND  MAN  47 

110.    PLANT   ZONES  -, 

Text-books.  Davis,  319-321.  Davis  Ele.,  353-357.  Dryer,  351-369. 
Gilbert  and  Brighara,  323-328.    Redway,  315-317.    Tarr,  339-344. 

Reference  books.  Bergen,  Foundations  of  Botany :  307-323,  Plant 
societies  ;  324-335,  Botanical  geography. 

CoxxMqv,  Plant  Studies :  177-187,  Water  plants  ;  188-213,  Drouth 
plants ;  214-220,  Plants  requiring  moderate  water  supply. 

Merriam,  Life  Zones  and  Crop  Zones  of  the  United  States:  18—53, 
Life  zones  of  the  United  States. 

Roth,  A  First  Book  of  Forestry:  37-40,  The  woods  and  the 
mountains. 

Russell,  North  America :  254-257,  The  treeless  mountain  tops. 

111.    THE  DISTRIBUTION  OF  ANIMALS 

Text-books.  Davis,  105-111.  Davis  Ele.,  338-349.  Dryer,  364- 
382.  Gilbert  and  Brigham,  328-331,  343-345.  Redway,  324-328. 
Tarr,  354-359. 

Reference  books.  Bailey,  Handbook  of  Birds  of  the  Western  United 
States:  xxxiii-xxxvi.  Life  zones. 

Jordan  and  Kellogg,  Animal  Life :  296-306,  Fauna  and  faunal 
areas. 

Russell,  North  America :  264-292,  Some  representative  mammals 
of  North  America. 

Shaler,  Story  of  Our  Continent:  196-205,  Animals  of  North 
America. 

112.   MIGRATIONS  AND  BARRIERS 

Text-books.  Davis,  54-56.  Davis  Ele.,  33a-334.  Dryer,  359- 
360.  Gilbert  and  Brigham,  340-343.  Redway,  309-313.  Tarr, 
345-346,  360-364. 

Reference  books.  Bailey,  Handbook  of  Birds  of  the  Western  United 
States:  xxxvi-xxxvii,  Migrations. 

Beal,  Seed  Dispersal:  4-11,  Plants  spread  by  means  of  roots; 
12-17,  Plants  multiply  by  means  of  stems ;  18-29,  Water  trans- 
portation of 'plants;    30-56,  Seeds   transported  by  wind;    58-60, 


48  PHYSICAL  GEOGRAPHY  MANUAL 

Plants  that  shoot  off  their  seeds ;  61-79,  Plants  that  are  carried 
by  animals ;  80-83,  Man  disperses  seeds  and  plants ;  84-87,  Some 
reasons  for  plant  migration. 

Bergen,  Foundations  of  Botany :  373-386,  How  plants  are  scat- 
tered. 

Coulter,  Plant  Studies :  112-122,  Dispersal  of  plants. 

Jordan,  Science  Sketches:  263''-266,  How  the  trout  crossed  the 
Rocky  mountains  into  Yellowstone  lake  ;  267-278,  How  the  trout 
came  to  California. 

Jordan  and  Kellogg,  Animal  Life :  272-283,  Laws  of  geograph- 
ical distribution  ;  283-288,  The  relation  of  species  to  habitat ;  288- 
296,  Character  of  barriers  to  distribution. 

Osterhout,  Experiments  with  Plants:  320''-325,  How  seeds  are 
scattered. 

Russell,  North  America :  292-298,  Migration  of  animals. 


113.    CHANGES  IN  PLANTS  AND  ANIMALS 

Text-books.  Davis  Ele.,  335-338.  Dryer,  360-363.  Gilbert  and 
Brigham,  339-340.     Tarr,  346-348,  364-365. 

Reference  books.  Bergen,  Foundations  of  Botany :  387-395,  The 
struggle  for  existence  and  the  survival  of  the  fittest. 

Coulter,  Plant  Studies :  142-148,  The  struggle  for  existence. 

Dodge,  Reader  in  Physical  Geography :  119-120,  Effects  of  cold 
and  frost  on  life. 

Heilprin,  The  Earth  and  Its  Story :  156-158,  The  variation  and 
extinction  of  animal  forms. 

Jordan,  Science  Sketches:  9-19,  The  story  of  a  salmon. 

Jordan  and  Kellogg,  Animal  Life :  114-122,  The  crowd  of  ani- 
mals and  the  struggle  for  existence. 

Osterhout,  Experiments  with  Plants:  409-417,  Mr.  Burbank's 
work  with  plums ;  422-427,  Mr.  Burbank's  work  with  the  Shasta 
daisy ;  429-434,  Methods  and  difficulties  of  crossing  and  selec- 
tion ;  434-441,  Experiments  with  corn  at  the  Illinois  Experiment 
Station. 

Pinchot,  Primer  of  Forestry,  Part  1 :  44-66,  The  life  of  a  forest. 

Shaler,  First  Book  in  Geology :  195-202,  How  species  are  made. 


PLANTS,  ANIMALS,  AND  MAN  49 

Shaler,  Sea  and  Land :  100''- 104,  The  struggle  for  existence  and 
the  origin  of  species. 

Shaler,  Story  of  Our  Continent:  14-17,  A  progression  of  forms 
of  life. 

114.    ECONOMIC   VALUE  OF  PLANTS  AND  ANIMALS 

Text-books.  Dryer,  385.  Eedway,  317-324,  328-331.  Tarr,  348- 
350,  365-360. 

Reference  books.  Bailey,  Handbook  of  Birds  of  the  Western  United 
States :  xxxvii-xxxix,  Economic  ornithology ;  xxxix-xliii.  The  pro- 
tection of  birds. 

Bailey,  Principles  of  Agriculture :  106-111,  The  oiSices  of  the 
plant ;  201-207,  The  offices  of  the  animal. 

Merriam,  Life  Zones  and  Crop  Zones  of  the  United  States:  9-17, 
Relations  of  the  United  States  Biological  Survey  to  practical 
agriculture. 

Roth,  A  First  Book  of  Forestry :  133-134,  Use  of  the  forest ; 
136-160,  Firewood,  pulp,  posts,  railway  ties,  etc. ;  174-177,  Resin 
and  turpentine,  seeds  and  mast ;  178-182,  Pasturage,  game,  and 
fish  ;  198-202,  Sand  dunes  checked  by  forests. 

Shaler,  Story  of  Our  Continent:  193-196,  Domesticated  plants 
of  North  America. 

Winslow,  Principles  of  Agriculture :  61-62,  Plants  purify  the  air. 

115.   FORESTS 

Text-books.  Dryer,  352-359.  Gilbert  and  Brigham,  319-323. 
Tarr,  349-350. 

Reference  books.  Brigham,  Geographic  Influences  in  American  His- 
tory :  279-285,  Forestry  a  federal  question ;  341*-346,  The  work 
of  the  United  States  Bureau  of  Forestry. 

Fairbanks,  Western  United  States :  278-289,  Forest  belts  of  the 
Sierra  Nevada  mountains ;  290-302,  National  parks  and  forest 
reserves. 

Muir,  Mountains  of  California:  247-254,  A  windstorm  in  the 
forest. 

Pinchot,  Primer  of  Forestry,  Part  I:  67-88,  Enemies  of  the 
forest. 


50  PHYSICAL  GEOGRAPHY  MANUAL 

Pinchot,  Primer  of  Forestry,  Part  II :  7-37,  The  practice  of 
forestry;  38-55,  Work  in  the  woods;  56-73,  The  weather  and  the 
streams  ;  74-88,  Forestry  abroad  and  at  home. 

Roth,  A  First  Book  of  Forestry :  14-18,  What  light  and  shade  do 
for  the  woods ;  18-24,  What  different  soils  do  for  the  woods ; 
24-32,  What  moisture  does  for  the  woods ;  32-37,  What  heat  and 
cold  do  for  the  woods ;  37-40,  The  woods  and  the  mountains ; 
41^5,  Use  not  abuse  of  the  woods ;  104-112,  Protection  against 
fire ;  195-198,  Forest  plantations  on  prairies ;  209-214,  Forests 
of  our  own  country  ;  214-216,  Some  history. 

Russell,  North  America:  215-218,  The  forests  of  North  America; 
219-227,  The  tropical  forests ;  227-235,  The  Atlantic  forest ;  235- 
237,  The  boreal  forest ;  238-249,  The  Pacific  forest. 

Shaler,  Outlines  of  the  Earth's  History :  341''-343%  Why  prairies 
are  treeless. 

Shaler,  Story  of  Our  Continent:  W2,-\2\,  Forests  of  North 
America. 

116.   NATURE   AND  MAN 

Text-books.  Davis,  1-7.  Davis,  Ele.,  349-353.  Dryer,  383-385. 
Gilbert  and  Brigham,  346-359.    Redway,  335-336.    Tarr,  369-375. 

Reference  books.  Shaler,  Story  of  Our  Continent :  153-157,  Indi- 
ans of  North  America;  157-161,  Indian  civilization;  161-165, 
Geographical  hindrances  to  Indian  civilization ;  Dodge,  Reader  in 
Physical  Geograjjhy :  213-221,  Defense,  etc. 

Fairbanks,  Western  United  States:  176-186,  The  Cliff  Dwellers 
and  their  descendants. 

Harrington,  About  the  Weather:  1-8,  Man's  conquest  of  nature 
takes  several  forms ;  9-16,  Civilization  has  many  disadvantages, 
especially  physical. 

117.    GEOGRAPHICAL  FACTORS  IN  THE   LIFE  OF 
CIVILIZED  PEOPLES 

Text-books.  Davis,  113-116.  Davis  Ele.,  364-372.  Dryer,  390- 
392.  Gilbert  and  Brigham,  315-318,  359-370.  Redway,  347-349, 
352-372.     Tarr,  375-380,  384-392. 


PLANTS,  ANIMALS,  AND  MAN  51 

Reference  books.  Brigham,  Geographic  Influences  in  American  His- 
tory:  18-22,  The  Erie  canal;  22-24,  Railroads  in  the  Mohawk 
valley ;  24-25,  The  railroads  across  the  Appalachians ;  25''-28, 
Geographic  conditions  favorable  to  New  York  city ;  50'*-52,  Water 
power  for  New  England  cities  ;  86-89,  Effect  of  the  Appalachian 
barrier  on  colonial  and  Revolutionary  history  ;  105-115,  Historical 
importance  of  the  Great  Lakes ;  126-141,  Importance  of  commerce 
of  the  Great  Lakes ;  160-172,  Physiography  and  commercial  alle- 
giance of  the  prairie  country ;  259-263,  Natural  causes  for  the 
development  of  towns  in  Colorado. 

Dodge,  Reader  in  Physical  Geography :  28-32,  Centers  of  life  ; 
33-46,  Agricultural  centers,  grazing  centers,  lumbering  centers ; 
47-58,  Manufacturing,  mining,  fishing,  hunting,  and  scenic  centers  ; 
194-197,  Climate  of  the  world  —  seasons  and  summary;  206-212, 
Water  supply  ;  222-227,  Transportation  and  power. 

Fairbanks,  Western  United  States:  205-214,  How  climate  and 
physical  features  influenced  the  settlement  of  the  West ;  268-277, 
Location  of  cities  of  the  Pacific  slope. 

Russell,  North  America :  365-376,  The  Eskimos,  the  Innuits,  the 
Aleutians ;  376-384,  The  Indians,  resources  and  natural  food  sup- 
ply ;  384-394,  Horticulture  and  houses  of  the  Indians ;  396-406, 
The  contact  of  the  aborigines  with  foreign  peoples. 

Shaler,  Story  of  Our  Continent:  9-12,  Life  of  man  modified 
by  geographical  conditions ;  161-165,  Geographical  hindrances 
to  Indian  civilization ;  233-245,  Effects  of  the  form  of  North 
America;  246-253,  Commerce  of  North  America;  262-278,  The 
natural  conditions  of  North  America  which  affected  its  settlement 
by  Europeans ;  166-169",  Influence  of  soil,  climate,  etc. 

118.    DISTRIBUTIOX  AXD  RACES  OF  MEN 

Text-books.    Dryer,  385-390.    Redway,  336-347.    Tarr,  381-383. 
Reference  book.    Dodge,  Reader  in  Physical  Geography :  228-231, 
Historical  distribution  of  people. 


Part  II 

FIELD  AXD  LABORATORY 
MANUAL 


FIELD  AND  LABORATORY 
MANUAL 


EXERCISE  I 
MAGNITUDES  AND  DISTANCES 

The  following  table  gives  approximately,  in  miles,  the  dis- 
tance of  each  of  the  eight  planets  from  the  sun,  the  diameter  of 
each  planet,  and  the  diameter  of  the  sun. 


Diameter 

Distance 

Diameter 

Distance 

Sun    . 

.  800,000 

0 

Jupiter    . 

.  80,000 

480,000,000 

Mercury 

.      3,000 

36,000,000 

Saturn 

.  70,000 

881,000,000 

Venus 

.      7,600 

67,000,000 

Uranus    . 

.  81,000 

1,772,000,000 

Earth, 

.      8,000 

93,000,000 

Neptune  . 

.  34,000 

2,770,000,000 

Mars  . 

.     .      4,200 

141,000,000 

Using  the  diameter  of  the  earth  given  above,  find  the  cir- 
cumference. How  long  would  it  take  an  express  train  to  go 
this  distance  at  the  rate  of  50  miles  per  hour?  In  a  similar 
manner  find  the  circumference  of  the  sun.  How  long  would  it 
take  the  express  train  just  mentioned  to  travel  this  distance? 
Using  the  scale  of  200,000  miles  to  the  inch,  draw  a  circle  to 
represent  the  sun.  Use  the  same  scale  and  draw  a  circle  at  the 
center  of  the  sun  to  represent  the  earth.  The  moon  is  about 
240,000  miles  distant  from  the  earth.  Place  a  dot  at  the  proper 
point  to  represent  this.  Imagine  the  earth  located  as  you  have 
drawn  it,  at  the  center  of  the  sun,  and  take  an  imaginary  trip 
from  the  earth  to  the  surface  of  the  sun.  After  reaching  the 
moon,  how  much  farther  would  you  have  to  go  ? 

65 


56  PHYSICAL   GEQGEAPHY  MANUAL 

The  volumes  of  two  spheres  are  to  each  other  as  the  cubes  of 
their  respective  diameters.  How  many  earths  would  it  take  to 
make  one  sun?  Jupiter  is  the  largest  of  the  planets.  How 
many  earths  would  it  take  to  make  a  Jupiter? 

Draw  on  the  blackboard  a  circle  to  represent  the  sun,  using 
the  scale  of  1,000,000  miles  to  the  inch.  How  large  is  the 
circle?  Use  the  same  scale  and  place  a  dot  to  represent  the 
distance  between  the  sun  and  Mercury;  between  the  sun  and 
Venus ;  between  the  sun  and  the  earth.  Make  the  dot  for  the 
earth  very  small ;  it  should  not  be  as  large  as  a  period  used  in 
printing  on  this  page.  Place  very  small  dots  to  represent  the 
positions  of  the  other  planets.  Are  there  any  planets  whose 
positions  you  cannot  represent  ?  Why  ?  Imagine  yourself  stand- 
ing on  the  sun  and  looking  at  the  planets ;  which  is  more  strik- 
ing, the  sizes  of  the  planets  or  the  distances  in  space  ? 

If  you  were  to  represent  the  position  of  the  nearest  fixed  star 
according  to  the  scale  last  used,  you  would  need  300  miles  of 
blackboard.  Light  travels  at  the  rate  of  186,000  miles  per  sec- 
ond. If  light  could  travel  in  a  circular  path,  how  many  times 
could  it  go  around  the  earth  in  a  second?  At  this  rate  how 
long  would  it  take  light  to  travel  from  the  sun  to  the  earth  ? 
How  long  from  the  sun  to  Neptune  ?  At  the  same  rate  it  would 
take  the  light  of  the  nearest  fixed  star  three  years  to  reach  the 
earth.  How  far  is  it  to  the  nearest  fixed  star?  This  is  how 
many  times  as  far  as  it  is  from  the  earth  to  the  sun?  Think  of 
this  at  night  when  you  look  at  the  stars. 

EXERCISE  II 
THE  OBLATENESS  OF  THE  EARTH 

Fasten  a  weight,  as  a  small  stone  or  heavy  bullet,  to  a  string 
and  whirl  it  with  the  hand  as  nearly  as  you  can  round  a  fixed 
point  on  the  table  top  or  on  the  floor.  What  is  the  shape  of  the 
path?  Trace  the  path  with  a  chalk  line.  Does  the  whirling 
weight  pull  on  the  string?  Whirl  it  rapidly.    Is  the  strength  of 


THE  OBLATENESS  OF  THE  EARTH       57 

the  pull  increased  or  decreased?  Whirl  it  rapidly  enough  to 
break  the  string.  What  becomes  of  the  weight?  Trace  its  path 
with  a  chalk  line.  What  shape  is  its  path  ?  What  relation  does 
it  sustain  to  the  former  path  ?  The  force  which  drives  it  along 
the  latter  path  is  called  centrifugal  ("  fleeing-from-the-center  ") 
force.  In  what  direction  with  reference  to  the  circumference 
does  centrifugal  force  act  on  a  whirling  body  ? 

What  force  acted  upon  the  moving  weight  before  the  string 
broke,  which  did  not  act  after  it  broke  ?  What  relation  does  the 
direction  of  this  force  sustain  to  the  circle  ?  This  force  is  called 
centripetal  ("  seeking-the-center")  force.  When  these  two  forces, 
centrifugal  and  centripetal,  act  at  the  same  time,  what  kind  of 
motion  may  result  ?  Make  a  drawing  in  your  notebook  similar 
to  the  one  drawn  in  chalk.  Place  arrows  to  show  the  direction 
of  the  motion.  Place  the  words  centrifugal  and  centripetal  on 
the  proper  lines  to  represent  the  directions  of  these  forces. 

Use  the  rotating  machine  and  brass  rings.  Cause  the  rings 
to  rotate  slowly.  What  shape  is  the  form  which  appears  ?  Which 
part  is  moving  more  rapidly,  the  part  near  the  axis  or  the  part 
midway  between  the  poles  ?  In  which  part  is  centrifugal  force 
greater  ?  Cause  the  rings  to  rotate  rapidly.  What  effect  has  this 
increase  of  speed  upon  the  centrifugal  force  midway  between 
the  poles  ?  What  change  is  there  in  the  shape  of  the  resulting 
form?  Account  for  this  difference  in  shape.  Make  a  draw- 
ing to  show  the  shape  when  rotating  slowly  and  another  to 
show  the  shape  when  rotating  rapidly.  Indicate  by  title  which 
is  which.  , 

How  do  you  know  that  the  earth  is  flattened  at  the  poles? 
How  was  the  fact  discovered?  Explain  how  it  may  have  ob- 
tained this  shape.  Have  we  proved  that  it  obtained  its  shape 
in  this  way?  If  this  theory  is  the  correct  one,  in  what  con- 
dition was  the  mass  of  the  earth  at  the  time  it  assumed  its 
present  form? 

What  name  is  given  to  the  centripetal  force  in  the  case  of 
the  earth's  rotation  ?  What  evidence  have  we  that  the  earth  is 
rotating  at  the  present  time  ? 


58  PHYSICAL   GEOGRAPHY  MANUAL 

EXERCISE   III 

THE    DIRECTION    OF    THE    AXIS   OF    THE    EARTH'S 
ROTATION 

Suspend  the  gyroscope^  by  a  string.  Carefully  balance 
it  and  cause  it  to  rotate  rapidly.  Carry  it  around  in  a  circu- 
lar path.  What  is  the  direction  of  the  axis  when  at  the  south 
side  of  the  circle?  at  the  east  side?  at  the  north  side?  at 
the  west  side?  Repeat  the  experiment  to  be  sure  that  your 
results  are  not  accidental.  What  relation  does  the  direc- 
tion of  the  axis  in  one  position  sustain  to  the  direction  in  any 
other  position  ? 

Grasp  the  gyroscope  firmly  by  the  handle  and  cause  it  to 
rotate  rapidly.  Hold  it  with  the  axis  pointing  east  and  west; 
then  quickly  turn  it  so  that  the  axis  points  north  and  south. 
Repeat  this  several  times.  Can  you  readily  change  the  direction 
of  its  axis  of  rotation  ? 

Observe  a  star  or  constellation  in  the  east  soon  after  sunset, 
and  again  after  two  or  three  hours.  What  change  has  occurred  ? 
What  is  the  cause  of  this  change  ?  Observe  the  same  star  again 
during  the  night,  and  again  the  next  evening  soon  after  sunset. 
Are  you  able  to  see  the  whole  of  its  path  ?    Why  ? 

Observe  a  star  in  the  north,  very  near  the  horizon,  and  again 
several  times  during  the  night.  What  change  has  occurred? 
What  is  the  cause  of  the  change?  What  is  the  shape  of  the 
apparent  path  of  the  star  ?  Can  you  see  the  whole  of  its  path  ? 
Is  there  a  star  that  does  not  have  this  apparent  motion?  Account 
for  this.  Describe  the  direction  of  the  earth's  axis  with  refer- 
ence to  the  stars.  Does  the  axis  always  retain  this  direction  ? 
How  do  you  know  ? 

Do  you  see  any  similarity  between  the  movements  of  the 
earth  and  those  of  the  gyroscope  ? 

1  The  gyroscope  may  be  homemade  by  mounting  a  small  heavy  wheel  on  an 
axis.     A  bicycle  wheel  with  ball  bearings  is  suggested. 


LENGTHS  OF  DAY  AND  NIGHT  59 

EXERCISE  IV 
LENGTHS   OF   DAY   AND   NIGHT 

Carry  a  globe  in  a  circle  round  a  pupil  who  will  represent 
the  sun.  From  data  so  obtained,  define  orbit  and  plane  of  orbit. 
Place  the  axis  of  the  globe  perpendicular  to  the  plane  of 
the  orbit  and  carry  the  globe  round  again.  Adjust  a  paste- 
board circle  so  that  it  will  exactly  bound  the  illuminated  por- 
tion of  the  globe  and  thus  separate  the  illuminated  portion 
from  the  dark  portion.  An  imaginary  circle  which  does  this  is 
called  the  circle  of  illumination.  Cause  the  globe  to  rotate. 
Compare  the  period  of  time  required  for  some  point  on  its  sur- 
face, say  your  own  town,  to  pass  through  the  illuminated  por- 
tion with  the  period  required  to  pass  through  the  dark  portion. 

What  angle  does  the  axis  of  the  earth  form  with  the  plane  of 
its  orbit  ?  (See  the  text-books.)  What  angle  does  it  make  with 
the  perpendicular  to  the  plane  of  the  orbit?  Place  the  globe 
with  its  axis  in  this  position.  Find  a  place  in  the  orbit  where 
the  lengths  of  day  and  night  are  equal  (first  position).  Move 
the  globe  from  this  position  through  one  fourth  of  the  orbit 
(second  position).  Be  sure  that  the  pasteboard  circle  is  properly 
adjusted.  Compare  the  period  of  time  that  it  now  takes  your 
town  to  pass  through  the  illuminated  part  with  the  period 
required  to  pass  through  the  dark  part.  Does  the  circle  of  illu- 
mination now  cut  your  circle  of  latitude  into  equal  or  unequal 
parts?  Compare  the  "day"  part  with  the  "night"  part.  Find 
another  position  (third  position)  in  the  orbit  where  the  days  and 
nights  are  equal  in  length.  Describe  this  position  with  refer- 
ence to  the  first.  Find  a  position  (fourth  position)  in  the  orbit 
where  the  relative  lengths  of  day  and  night  are  the  reverse  of 
what  they  are  in  the  second  position.  Compare  the  relative  parts 
into  which  the  circle  of  illumination  cuts  your  circle  of  latitude 
with  the  relative  lengths  of  day  and  night.  At  what  time  of 
year  do  you  find  conditions  existing  similar  to  those  of  the  first 
position?  the  third  position?  the  second  position?  the  fourth 
position  ?    Give  names  to  these  particular  times  of  the  year. 


60  PHYSICAL  GEOGRAPHY  MANUAL 

EXERCISE  V 
NORTH    AND   SOUTH    LINE 

Set  a  post  in  the  ground  so  that  the  top  will  be  about  two 
feet  above  the  surface.  A  broomstick  makes  a  good  post.  By 
means  of  a  plumb  line  make  this  post  vertical,  and  with  it  as 
a  center  draw  a  circle  on  the  ground  with  a  radius  of  57.3 
inches.  What  is  the  circumference  of  this  circle?  How  many- 
degrees  are  there  in  a  circle?  What  is  the  length  of  one  degree 
of  this  circle  ? 

What  direction  is  taken  by  the  first  shadow  which  is 
cast  by  the  post  in  the  morning?  Give  direction  and  length 
of  shadow  at  9  a.m.  ;  at  noon ;  at  3  p.m.  What  change  in 
the  length  of  the  shadow  occurs  in  the  forenoon?  in  the 
afternoon  ? 

At  some  time  in  the  forenoon  the  end  of  the  shadow  will 
cross  the  circumference  of  the  circle.  Mark  the  point  where  it 
just  touches  the  circumference.  Do  the  same  in  the  afternoon. 
Connect  these  two  points  "with  a  straight  line.  This  line  is  due 
east  and  west.  Divide  it  exactly  in  the  middle.  Draw  a  line 
from  this  middle  point  to  the  center  of  the  post.  Extend  the 
last  line  until  it  cuts  the  circumference  on  opposite  sides.  What 
angle  does  the  last  line  form  with  the  first?  In  what  direc- 
tion does  the  last  line  extend?  Draw  a  line  due  east  and  west 
through  the  center  of  the  post.  Make  a  drawing  to  show  the 
circle,  the  position  of  the  post,  and  the  lines.  Use  letters  to 
indicate  directions. 

At  night  observe  the  north  star  and  place  a  mark  on  the 
circumference  so  that  the  mark,  the  post,  and  the  north  star  shall 
be  in  a  straight  line.  From  this  point  draw  a  diameter.  In 
what  direction  does  the  diameter  extend  ?  If  this  line  does  not 
coincide  with  the  other  north  and  south  line,  account  for  the 
difference.  Do  you  know  of  any  other  method  by  which  you 
might  determine  true  north? 


THE  APPARENT  MOVEMENTS  OF  THE  SUN       61 


EXERCISE   VI 


THE   APPARENT   MOVEMENTS   OF   THE   SUN 


Part  I 

Use  the  circle  drawn  in  Exercise  V.  Stand  so  that  the  center 
of  the  post  is  between  you  and  the  point  of  sunrise.  Make  a 
mark  on  the  circumference  of  the  circle,  such  that  it  will  be  in 
line  with  the  point  of  sunrise  and  the  post.  Is  the  point  of  sun- 
rise due  east?  If  not,  how  many  de- 
grees north  or  south  of  due  east  is  it? 
(Should  you  find  the  point  of  sunrise 
5  degrees  south  of  due  east,  its  direction 
would  be  read  "  east, 
5  degrees  south.") 
Make  a  similar  ob- 
servation for  sunset. 
When  the  sun  is  due 
south  it  is  said  to  be 
on  our  meridian,  and 
we  call  the  hour  noo)i. 
By  the  use  of  the 
clinometer  (Fig.  1) 
determine  the  angle 
of  elevation  of  the 
sun  when  it  is  on 
our  meridian.  (The 
angle  of  elevation  is 
the  angle  that  a  ray 
of  light  from  the  sun 
makes  with  the  plane 
of  the  horizon.)  Set 
your  watch  by  the 
sun  at  noon  and  from  that  determine  the  exact  times  of  sunrise 
and  sunset.  From  this  determine  the  length  of  the  day  from 
sunrise  to  sunset. 


Fig.  1.   The  Clinometer 

When  the  clinometer  is  held  so  that  the  line  AB  is 
horizontal,  the  vertical  line  DO  coincides  with  the 
Hue  CO.  When  it  is  used  to  determine  a  vertical 
angle,  AB  is  pointed  at  the  object  of  observation. 
DO  then  departs  from  CO  as  much  as  AB  does 
from  the  horizontal,  hence  angle  COD  is  the  angle 
of  elevation 

In  determining  the  angle  of  elevation  of  the  sun,  hold 
the  clinometer  so  that  the  shadow  of  the  pin  at  A 
or  at  B  falls  on  the  line  AB.  Angle  COD  is  then 
the  desired  angle 


62  PHYSICAL  GEOGEAPHY  MANUAL 

Make  observations  similar  to  the  preceding  every  two  weeks 
and  tabulate  your  results,  giving,  in  different  columns,  (a)  date, 
(b)  direction  of  sunrise,  (c)  direction  of  sunset,  (d)  time  of  sun- 
rise, (e)  time  of  sunset,  (/)  length  of  day,  (g)  elevation  of  the 
sun  at  noon. 

Part  II 

When  is  the  day  longest?  When  shortest?  When  are  days 
and  nights  of  equal  length?  How  many  times  each  year  are 
the  days  and  nights  of  equal  length?  Is  the  sun  ever  directly 
over  your  head?  Is  it  ever  north  of  you  at  noon?  At  what 
time  of  day  does  the  sun  shine  on  the  north  side  of  the  house  ? 
Explain  how  this  can  be.  During  what  months  do  you  find  the 
greatest  difference  between  successive  readings  in  the  second 
and  third  columns  of  your  table  ?  Compare  this  with  the  times 
of  the  equinoxes  and  the  solstices. 

Part  III 

Carry  a  globe  in  a  circular  path  about  a  pupil,  who  will 
represent  the  sun.  Adjust  the  globe  so  that  the  axis  shall  be 
perpendicular  to  the  plane  of  its  orbit.  What  then  is  the  angle 
of  noon  elevation  of  the  sun  to  an  observer  at  the  equator? 
Hold  a  card  tangent  to  the  globe  at  40  degrees  north  latitude  on 
the  side  nearest  to  the  sun,  to  represent  the  plane  of  the  horizon 
of  an  observer  at  that  point.  What  is  the  angle  of  noon  eleva- 
tion of  the  sun  to  an  observer  at  this  point?  (All  the  rays  of 
light  which  reach  the  earth  from  the  sun  are  practically  parallel. 
Consider  their  direction  as  parallel  to  a  line  joining  the  center 
of  the  sun  and  the  center  of  the  earth.)  Cause  the  earth  to 
revolve  about  the  sun.  Note  and  record  any  change  in  the 
angle  of  noon  elevation  of  the  sun. 

Adjust  the  globe  so  that  the  axis  shall  be  inclined  20  degrees 
from  the  perpendicular.  What  is  the  angle  of  noon  elevation 
of  the  sun  at  the  time  of  the  equinox  to  an  observer  at  the 
equator?  to  an  observer  at  40  degrees  north  latitude?  Cause 
the  earth  to  revolve  about  the  sun.    The  greatest  angle  of  noon 


THE  APPARENT  MOVEMENTS  OF  THE  SUN        63 

elevation  of  the  sun  is  made  at  the  time  of  the  summer  solstice. 
Determine  and  record  this  angle.  When  is  the  smallest  angle 
made?  Determine  and  record  this  angle.  What  is  the  differ- 
ence (in  degrees)  between  the  greatest  and  the  smallest  angle  ? 
Compare  this  with  the  angle  of  inclination  (20  degrees). 

Repeat  this  part  of  the  experiment,  having  the  axis  of  the 
earth  inclined  40  degrees  from  the  perpendicular,  and  make 
the  same  comparison  as  before.  Give  a  rule  for  determining  the 
difference  between  the  greatest  and  the  smallest  angle  (noon 
elevations),  when  the  angle  of  inclination  of  the  earth's  axis  is 
given.  Give  a  rule  for  determining  the  angle  of  inclination 
of  the  earth's  axis,  when  you  have  the  greatest  and  the  smallest 
angle  of  noon  elevation  of  the  sun.  Apply  this  rule  to  the  noon 
elevations  given  in  your  table  and  determine  the  true  angle  of 
inclination  of  the  earth's  axis.  Compare  this  with  the  angle 
given  by  the  books. 

Part  IV 

Use  cross-section  paper  and  mark  out  a  rectangle  26  squares 
long  and  24  squares  wide.  Draw  a  line  lengthwise  through 
the  center  of  the  rectangle.  Let  each  square  lengthwise  repre- 
sent two  weeks  of  time.  Write  opposite  each  line  a  date  from 
your  table  of  observations.  Let  each  square  crosswise  represent 
an  hour  of  the  day.  Let  the  line  through  the  center  represent 
noon.  Place  figures  to  indicate  the  hour  represented  by  each 
line.  Distinguish  between  forenoon  and  afternoon.  Place  a 
dot  at  the  proper  point  to  represent  the  hour  of  sunrise  on  the 
date  of  your  first  observation.  Do  the  same  for  the  hour  of 
sunset.  Make  dots  in  the  proper  positions  for  all  other  obser- 
vations recorded  in  the  table.  In  like  manner  represent  the 
times  of  sunrise  and  sunset  for  that  portion  of  the  year  not 
included  in  your  table.  (Use  the  almanac.)  Draw  a  line  through 
as  many  of  the  sunrise  dots  as  possible,  to  make  a  somewhat 
regular  curve.  We  call  this  line  the  sunrise  curve.  Draw  the 
su7iset  curve.  Shade  the  night  portion  of  your  diagram,  leaving 
the  day  portion  white.  Give  the  completed  diagram  the  title 
"  Sunset  and  Sunrise  Curves  from  —  to  — ,"  giving  the  dates. 


64  PHYSICAL  GEOGEAPHY  MANUAL 

EXERCISE  VII 
THE    MOON 

Refer  to  the  almanac,  determine  the  date  of  the  next  new 
moon,  and  look  for  it  on  the  evening  of  that  day.  If  you 
do  not  see  it,  look  again  the  next  evening.  Make  a  draw- 
ing of  the  moon  as  it  appears  when  you  first  see  it.  Observe 
the  moon  at  sunset  two  days  later  and  make  a  drawing. 
Make  a  drawing  every  two  days  until  the  moon  is  full.  Give 
your  drawings  a  title,  giving  in  each  case  the  age  of  the  moon 
in  days,  counting  from  the  date  of  the  new  moon.  In  what 
part  of  the  heavens  did  you  first  see  the  new  moon?  What 
change  in  position  occurs  on  successive  evenings?  In  what 
direction  does  the  moon  move  round  the  earth?  How  do  you 
know  ?  In  what  length  of  time  does  the  moon  make  one  revo- 
lution round  the  earth?  (Calculate  the  exact  time  in  days, 
hours,  minutes,  and  seconds  from  one  new  moon  to  the  next 
succeeding,  as  given  in  the  almanac.) 

Place  a  slated  globe  on  the  table  and  whiten  the  side  which 
would  be  illuminated  by  the  setting  sun,  if  its  light  could  fall 
on  the  globe.  How  much  of  the  surface  of  the  globe  would  be 
illuminated?  Let  this  globe  represent  the  moon  and  allow  one 
pupil  to  carry  it  entirely  round  the  room,  always  keeping  the 
white  side  toward  the  direction  of  the  setting  sun.  How  much 
of  the  surface  is  illuminated  when  the  globe  is  south  of  you? 
How  much  of  the  illuminated  part  can  you  see?  What  phase 
of  the  moon  does  this  represent?  How  much  of  the  surface  is 
illuminated  when  the  globe  is  east  of  you  ?  How  much  of  the 
illuminated  part  can  you  see?  What  phase  does  this  represent? 
In  which  direction  from  you  is  the  globe  when  it  represents 
the  new  moon? 

Make  a  drawing  to  represent  the  surface  of  the  moon  as  seeii 
through  the  telescope. 


LATITUDE  65 

EXERCISE  VIII 
LATITUDE 

If  you  were  at  the  equator,  where  would  the  sun  appear  at 
noon  at  the  time  of  the  equinox?  What  would  be  its  noon 
elevation  in  degrees?  Where  would  the  sun  appear  at  this 
time  if  you  were  at  the  north  pole?  (Remember  that  the 
sun  is  so  remote  from  the  earth  that  rays  coming  to  the  pole 
are  practically  parallel  with  those  coming  to  the  equator.) 
What  would  be  the  sun's  noon  elevation  at  the  north  pole? 
What  would  be  its  noon  elevation  if  you  lived  30  degrees 
north  of  the  equator?  If  its  noon  elevation  were  50  degrees, 
what  would  be  your  latitude?  Give  a  rule  for  finding  your 
latitude  from  the  noon  elevation  of  the  sun  at  the  time  of 
the  equinox.  From  your  table  of  observations  (Exercise  VI) 
determine  your  latitude  according  to  this  rule.  If  the  result 
is  not  correct,  account  for  your  error.  Is  your  rule  correct 
for  noon  elevations  taken  at  any  time  of  the  year?  Give  a 
reason  for  this. 

Use  the  clinometer  and  take  the  elevation  of  the  north  star. 
Compare  this  with  your  latitude.  What  change  would  occur  in 
the  elevation  of  the  north  star  if  you  should  go  toward  the 
north  pole?  Where  would  it  appear  if  you  should  reach  the 
north  pole?  What  would  then  be  its  elevation?  What  is 
the  latitude  of  the  north  pole?  What  is  the  latitude  of  the 
equator?  What  would  be  the  elevation  of  the  north  star  at 
the  equator?  Where  would  the  north  star  appear  to  one  living 
in  the  southern  hemisphere? 

Where  does  the  line  of  your  latitude  strike  Europe?  What 
places  in  North  America  are  in  the  latitude  of  London, 
England? 

If  a  straight  line  were  drawn  from  your  home  through  the 
center  of  the  earth,  in  what  latitude  would  it  pierce  the  sur- 
face on  the  opposite  side  ?  In  what  longitude  would  this  be  ? 
Examine  the  globe  to  see  if  your  answers  are  correct. 


66  PHYSICAL  GEOGRAPHY  MANUAL 

If  you  were  to  go  due  south  from  St.  Louis,  Missouri,  to  the 
South  Pole,  over  what  land  and  through  what  waters  would  you 
pass?  Name  another  town  approximately  in  the  longitude  of 
New  York  ;  of  Tokio ;  of  Cape  Town. 


EXERCISE   IX 

SOME   PROPEKTIES   OF   THE   ATMOSPHERE 

Part  I 

Aim.    To  ascertain  whether  air  has  weight. 

Apparatus.  Balance  and  weights,  electric-light  bulb  in  which 
there  is  no  air,  Bunsen  burner,  blowpipe. 

Procedure.  Suspend  the  electric-light  bulb  from  the  hook 
on  one  pan  of  the  balance.  Put  weights  into  the  other  pan 
until  the  bulb  is  counterpoised  as  perfectly  as  possible.  Use 
the  blowpipe  and  blow  the  flam.e  of  the  Bunsen  burner  against 
the  bulb  until  a  hole  is  made  in  it.  Is  the  bulb  now  perfectly 
counterpoised?    Is  it  heavier  or  lighter  than  it  was  before? 

Conclusion.    Has  air  weight? 

Part  II 

Aim.    To  ascertain  whether  air  exerts  pressure. 

Apparatus.    The  same  as  in  Part  I. 

Procedure.  Observe  the  opening  made  in  the  bulb  in  Part  I. 
Is  the  glass  bent  out  or  in  around  the  opening?  What  force 
made  the  hole  in  the  glass?    Why  was  heat  applied  to  it? 

Conclusion.    Does  air  exert  pressure  ? 

Part  III 

Aim.    To  ascertain  in  what  directions  air  exerts  pressure. 

Apparatus.  The  same  as  in  Parts  I  and  II,  with  the  addition 
of  an  air  pump  and  a  bell  jar. 

Procedure.  Remove  the  bell  jar  to  see  that  it  is  not  fastened 
to  the  plate  of  the  air  pump.    Place  it  again  on  the  plate  and 


CONSTITUENTS  OF  THE  ATMOSPHERE  67 

exhaust  the  air.  Try  to  lift  it  again.  What  success  do  you 
have?  Account  for  this.  In  which  direction  does  this  prove 
that  the  air  presses?  Observe  the  opening  made  in  the  bulb 
in  Parts  I  and  II.  Was  it  made  by  pressure  downward  or  from 
one  side  ?  Suppose  the  flame  had  been  applied  to  the  bottom  of 
the  suspended  bulb.  Would  an  opening  have  been  made  as 
before?  If  you  are  not  sure,  try  it.  Does  air  exert  pressure 
upward  ? 

Conclusion.    In  what  directions  does  air  exert  pressure? 


EXERCISE   X 
CONSTITUENTS   OF    THE    ATMOSPHERE 

Observe  the  color  and  odor  of  oxygen.  Partially  burn  a  match 
and  blow  it  out,  leaving  the  end  glowing.  Insert  this  into  the 
bottle  of  oxygen.  Wliat  occurs  ?  Repeat  the  process  to  be  sure 
that  it  is  not  an  accident.  Oxygen  is  sometimes  called  the  sup- 
porter of  combustion.  Will  air  support  combustion  ?  Why  will 
the  fire  in  a  stove  burn  better  when  the  "draught"  is  open? 

Attach  a  small  quantity  of  steel  wool  to  the  end  of  a  wire. 
Heat  it  red-hot  in  the  flame  of  the  Bunsen  burner  and  insert  it 
into  the  bottle  of  oxygen.  What  occurs  ?  Will  air  support  the 
combustion  of  steel  ?  Compare  air  and  oxygen  as  supporters  of 
combustion.    How  do  you  account  for  the  difference  ? 

Attach  a  small  candle  to  the  top  of  a  flat  cork  and  float  it  on 
a  vessel  of  water.  Invert  over  it  a  tumbler  with  straight  sides, 
keeping  the  mouth  of  the  tumbler  under  water.  What  occurs  ? 
Account  for  this.  When  the  tumbler  was  inverted  it  was  full 
of  gas  (air).  Is  it  now  full  of  gas  ?  Keep  the  water  line  inside 
and  outside  the  tumbler  at  the  same  level  and  measure  the 
length  of  that  part  now  filled  with  gas.  What  proportion  of  the 
whole  length  of  the  tumbler  is  it  ?  What  proportion  of  the  whole 
quantity  has  been  used  up  ?  According  to  this,  what  proportion 
of  tlie  air  is  oxygen  ?  According  to  the  books,  what  proportion 
of  the  air  is  oxygen?    What  gas  is  found  in  the  air  in  largest 


68  PHYSICAL  GEOGRAPHY  MANUAL 

quantity  ?  If  the  proportion  of  this  gas  were  not  so  large,  what 
difference  would  there  be  in  the  rate  of  the  burning  of  a  building? 

Cut  a  paraffin  candle  into  pieces  about  half  an  inch  long. 
Place  three  or  four  such  pieces  about  six  inches  apart  in  the 
bottom  of  a  V-shaped  trough.  Incline  the  trough  at  an  angle 
of  from  20  to  45  degrees  with  the  horizontal.  Invert  a  bottle  of 
carbon  dioxide  above  the  upper  end  of  the  trough  and  remove 
the  stopper.  What  results?  Is  carbon  dioxide  a  supporter  of 
combustion  ?  Is  it  a  heavy  or  a  light  gas  ?  Describe  the  color 
and  odor  of  this  gas. 

Summary.  Name  the  three  most  important  gases  found  in 
the  atmosphere  and  give  the  proportion  of  each.  Give  color 
and  odor  of  each.    Of  what  use  is  each? 


EXERCISE  XI 

COMBUSTION  AND  OXIDATION 

Part  I 

Heat  a  small  mass  of  steel  wool  red-hot,  thus  burning  off  all 
oil.  Place  it  on  a  cork,  moisten  it  thoroughly,  and  float  the 
cork  on  water.  Invert  a  wide-mouthed  bottle  over  the  floating 
cork  and  support  it  with  its  mouth  just  beneath  the  surface  of 
the  water.  Note  carefully  the  height  of  the  water  in  the  inverted 
bottle.  Leave  it  in  this  position  over  night.  In  the  morning 
again  observe  the  height  of  the  water  within  the  bottle.  Com- 
pare the  amount  of  air  now  in  the  bottle  with  the  amount  there 
the  day  before.  The  part  which  disappeared  was  oxygen.  Where 
do  you  suppose  it  went?  What  change  do  you  notice  in  the 
appearance  of  the  steel  wool?  The  new  substance  which  has 
appeared  is  called  an  oxide  of  iron.  What  can  you  see  appro- 
priate in  this  name  ?  What  is  the  common  name  for  this  par- 
ticular oxide  of  iron?  The  process  which  you  have  observed 
is  called  oxidation.  Define  oxidation.  Oxidation  is  sometimes 
called  slow  combustion.  What  can  you  see  appropriate  in  this 
name? 


EVAPORATION  AND  CONDENSATION  69 

What  is  the  color  of  the  oxide  of  iron  which  you  have 
observed  above  ?  A  very  common  color  of  oxide  of  iron  is  red. 
Examine  and  describe  red  ocher.  Oxide  of  iron  is  the  sub- 
stance that  nature  has  used  to  "  paint  the  rocks  red."  Red  and 
brown  sandstone  are  usually  colored  with  this  material.  Look 
for  red,  yellow,  or  rusty  spots  in  blocks  of  sandstone  or  lime- 
stone. Bricks  are  usually  red  because  the  iron  in  the  clay  is 
oxidized  in  the  process  of  burning. 

Part  II 

What  is  the  object  of  burning  wood  or  other  fuel  in  the 
stove  ?  Does  the  combustion  of  steel  wool  (Exercise  X)  accom- 
plish the  same  result  ?  How  do  you  know  ?  What  is  the  essen- 
tial gas  in  this  process  ? 

In  breathing,  the  oxygen  is  removed  from  the  air  in  the  lungs 
and  is  conveyed  by  the  blood  to  all  parts  of  the  body.  Here  it 
unites  with  the  various  tissues.  Characterize  this  oxidation  of 
the  tissues  as  rapid  or  slow  combustion.  Compare  the  result 
with  the  result  of  burning  wood.  What  gas  is  essential  in 
breathing  ?    W hy  ? 

Did  you  ever  notice  that  the  temperature  in  a  heap  of  decay- 
ing vegetable  matter  or  about  an  old  rotting  log  is  different 
from  the  temperature  of  surrounding  objects  ?  If  so,  what  dif- 
ference did  you  notice  ?  In  what  respects  does  decay  resemble 
combustion  ?    ^ 

EXERCISE  XII 
EVAPORATION  AND  CONDENSATION 

Place  a  shallow  vessel  in  one  pan  of  the  balances  and  partly 
fill  it  with  water.  Weigh  it  carefully  and  let  it  stand  for  sev- 
eral hours  (or  over  night)  in  a  place  where  there  is  a  circulation 
of  air.  Weigh  it  again  and  compare  with  the  first  weight. 
Account  for  any  change.  The  part  which  disappears  is  called 
vapor  and  the  process  is  called  evaporation.  Is  water  vapor 
visible  ? 


70  PHYSICAL  GEOGRAPHY  MANUAL 

Put  a  drop  of  water  on  the  table  top.  Set  a  watch  crystal 
filled  with  ether  in  the  water  and  cause  a  breeze  to  blow  over 
it,  by  fanning  or  blowing,  until  the  ether  is  evaporated.  Lift 
the  watch  crystal.  What  change  has  occurred  in  the  water? 
Has  the  water  gained  or  lost  heat?  Has  the  watch  crystal 
gained  or  lost  heat?  The  ether  in  evaporating  took  up  and 
carried  away  the  heat. 

Put  a  drop  of  alcohol  in  the  palm  of  the  hand.  What  sensa- 
tion is  felt?  What  becomes  of  the  heat?  Why  do  we  wrap  a 
wet  cloth  around  a  water  jar  ?  Is  it  desirable  that  the  water  in 
the  cloth  should  evaporate  ?  Where  does  the  heat  go  in  such  a 
case  ?    Where  does  it  come  from  ? 

Fill  a  teakettle  half  full  of  water  and  cause  it  to  boil  vigor- 
ously. Does  the  water  evaporate?  Characterize  this  as  rapid 
or  slow  evaporation.  How  may  rapid  evaporation  be  produced  ? 
Place  some  cold  object  just  in  front  of  the  spout  of  the  boiling 
kettle.  What  occurs?  What  effect  did  the  presence  of  the 
cold  object  have  on  the  temperature  of  the  water  vapor?  What 
name  is  given  to  the  process  resulting  from  such  a  change  of 
temperature?  How  did  this  affect  the  temperature  of  the  cold 
object?  Does  condensation  give  heat  to  surrounding  objects  or 
take  heat  from  them? 

True  water  vapor  is  invisible.  Do  you  find  an  area  of  true 
water  vapor  very  near  the  end  of  the  spout  ?  What  change  has 
occurred  to  make  it  visible  farther  away  from  the  spout?  Why 
does  this  change  occur  ?  Which  is  capable  of»  holding  more 
water  vapor,  warm  air  or  cold? 


EXERCISE  XIII 
HUMIDITY 

Humidity  is  the  moisture  in  the  atmosphere.  When  the  atmos- 
phere contains  all  the  moisture  that  it  possibly  can,  it  is  said  to 
be  saturated.  Take  the  temperature  and  measure  the  dimen- 
sions of  the  laboratory.    Refer  to  Table  A  and  calculate  the 


HUMIDITY  71 

capacity  of  this  room  for  water  vapor,  that  is,  the  amount  of 
water  vapor  it  is  capable  of  holding  at  this  temperature.  Give 
the  capacity  in  pounds.  Does  the  room  always  have  this  amount 
of  water  vapor  in  it  ?  The  amount  actually  present,  measured 
in  grains  per  cubic  foot,  is  called  the  absolute  humidity. 

Observe  the  wet  and  the  dry  bulb  thermometers.  Take  the 
reading  of  the  dry  bulb  thermometer  and  record  it.  This  gives 
the  temperature  of  the  room.  Read  the  wet  bulb  thermometer 
and  record  it.  Compare  this  with  the  former  reading.  Why  is 
there  this  difference  ?  If  the  air  is  very  dry,  it  will  drink  up 
the  water  from  the  wet  bulb  very  rapidly.  What  effect  will  this 
have  on  the  temperature  recorded  by  the  wet  bulb  thermometer? 
Will  this  increase  or  decrease  the  difference  between  the  read- 
ings of  the  two  thermometers?  The  ratio  of  the  absolute 
humidity  to  the  capacity  is  called  the  relative  humidity.  When 
the  air  is  very  dry,  is  the  relative  humidity  great  or  small? 
When  the  difference  between  the  readings  of  the  wet  and  the 
dry  bulb  thermometers  is  great,  is  the  relative  humidity  great  or 
small  ?  Refer  to  Table  B  and  find  the  relative  humidity  in  the 
laboratory.  Tell  how  you  found  it.  You  have  calculated  the 
capacity  of  the  laboratory,  and  now  you  know  what  per  cent 
of  this  amount  is  actually  present.  From  this  calculate  and 
record  the  weight  of  the  water  vapor  now  in  the  room.  Give 
the  weight  in  pounds. 

Fill  a  brightly  polished  metal  cup  or  can  about  half  full  of 
water  at  the  temperature  of  the  room.  Gradually  pour  in  ice 
water,  stirring  all  the  time,  until  a  trace  of  moisture  can  be 
seen  on  the  outside  of  the  cup.  Where  does  this  moisture 
come  from?  Can  you  see  it  before  it  cond-enses?  Compare 
the  temperature  of  the  can  with  that  of  the  room.  How 
must  the  can  affect  the  temperature  of  the  air  in  its  immediate 
vicinity?  Why  does  moisture  condense  on  the  surface  of  the 
can  and  not  on  other  objects  in  the  room  ?  Carefully  take  and 
record  the  temperature  of  the  water  in  the  can.  Allow  the  can 
to  stand  and  become  warmer  until  the  moisture  disappears. 
Take  the  temperature  again  and  record  it.    Average  these  two 


72 


PHYSICAL  GEOGEAPHY  MANUAL 


readings.  The  average  is  called  the  dew-point  of  the  air  at  this 
particular  time.  The  air  immediately  around  the  cup  is  at  the 
dew-point.  Is  it  at  the  dew-point  elsewhere  in  the  room?  To 
what  temperature  must  the  air  in  the  room  fall  before  dew  will 
gather  on  objects  in  the  room  ? 

When  the  air  is  at  the  dew-point,  the  relative  humidity  is  100 
per  cent.  What  does  this  mean  ?  When  the  absolute  humidity 
is  great,  is  the  dew-point  reached  at  a  high  or  a  low  tempera- 
ture ?  Is  dew-point  always  at  the  same  temperature  ?  Does  the 
air  always  have  the  same  amount  of  water  vapor  in  it?  Why 
does  dew  form  on  some  nights  and  not  on  others  ? 

Define  humidity ;  capacity  for  water  vapor ;  absolute  humid- 
ity; relative  humidity;  dew-point. 

TABLE  A 

Grains  of  Water  Vapor  in  a  Cubic  Foot  of  Saturated  Air 
AT  Various  Temperatures 


Deg. 

Grains 

Deg. 

Grains 

Deg. 

Grains 

Deo. 

Grains 

10 

.776 

34 

2.279 

58 

5.370 

82 

11.626 

12 

.856 

36 

2.457 

60 

5.745 

84 

12.356 

14 

.941 

38 

2.646 

62 

6.142 

86 

13.127 

16 

1.032 

40 

2.849 

64 

6.563 

88 

13.937 

18 

1.128 

42 

3.064 

66 

7.009 

90 

14.790 

20 

1.235 

44 

3.294 

68 

7.480 

92 

15.689 

22 

1.355 

46 

3.539 

70 

7.980 

94 

16.634 

24 

1.483 

48 

3.800 

72 

8.508 

96 

17.626 

26 

1.623 

50 

4.076 

•  74 

9.066 

98 

18.671 

28 

1.773 

52 

4.372 

76 

9.655 

100 

19.766 

30 

1.935 

54 

4.685 

78 

10.277 

102 

20.917 

32 

2.113 

56 

5.016 

80 

10.934 

104 

22.125 

HUMIDITY  73 

TABLE  B,  FOR  FINDING  RELATIVE   HUMIDITY 


>  s 

DlFFEREXCE  BETWEEN  READINGS  OF  THE  DKY  AND  THE  WET  BCLB 

s« 

1 

2 

3 

4 

5 

6 

7 

8 

9 

10 

11 

12 

13 

14 

16 

16 

17 

18 

19 

20 

0 

68 

35 

3 

2 

71 

41 

12 

4 

73 

46 

19 

6 

75 

50 

25 

1 

8 

77 

54 

31 

9 

10 

79 

57 

36 

15 

12 

80 

60 

41 

21 

3 

14 

82 

63 

45 

29 

10 

16 

83 

66 

49 

33 

16 

18 

84 

68 

63 

38 

22 

7 

20 

85 

70 

66 

42 

28 

14 

22 

86 

72 

69 

45 

32 

19 

7 

24 

87 

74 

61 

49 

36 

24 

12 

26 

88 

75 

64 

52 

40 

29 

18 

7 

28 

88 

77 

66 

55 

44 

33 

23 

12 

2 

30 

89 

78 

68 

67 

47 

37 

27 

17 

8 

32 

90 

79 

69 

60 

60 

41 

31 

22 

13 

4 

34 

90 

81 

72 

62 

63 

44 

35 

27 

18 

9 

1 

36 

91 

82 

73 

65 

56 

48 

39 

31 

23 

14 

6 

38 

91 

83 

75 

67 

69 

51 

43 

36 

27 

19 

12 

4 

40 

92 

84 

76 

68 

61 

63 

46 

38 

31 

23 

16 

9 

2 

42 

92 

85 

77 

70 

62 

66 

48 

41 

34 

28 

21 

14 

7 

44 

93 

85 

78 

71 

64 

57 

61 

44 

37 

31 

28 

18 

12 

5 

46 

93 

86 

79 

72 

66 

59 

63 

46 

40 

34 

28 

22 

16 

10 

4 

48 

93 

87 

80 

73 

67 

60 

54 

48 

42 

36 

31 

25 

19 

14 

8 

3 

50 

93 

87 

81 

74 

68 

62 

56 

50 

44 

39 

33 

28 

22 

17 

12 

7 

2 

52 

94 

88 

81 

75 

69 

63 

58 

62 

46 

41 

36 

30 

25 

20 

16 

10 

6 

54 

94 

88 

82 

76 

70 

66 

59 

54 

48 

43 

38 

33 

28 

23 

18 

14 

9 

6 

56 

94 

88 

82 

77 

71 

66 

61 

55 

60 

46 

40 

35 

31 

26 

21 

17 

12 

8 

4 

58 

94 

89 

83 

77 

72 

67 

62 

67 

52 

47 

42 

38 

33 

28 

24 

20 

15 

11 

7 

3 

60 

94 

89 

84 

77 

73 

68 

63 

58 

63 

49 

44 

40 

35 

31 

27 

22 

18 

14 

10 

6 

62 

94 

89 

84 

79 

74 

69 

64 

60 

56 

50 

46 

41 

37 

33 

29 

25 

21 

17 

13 

9 

64 

95 

90 

85 

79 

75 

70 

66 

61 

66 

62 

48 

43 

39 

35 

31 

27 

23 

20 

16 

;2 

66 

95 

90 

86 

80 

76 

71 

66 

62 

58 

53 

49 

45 

41 

37 

33 

29 

26 

22 

18 

15 

68 

96 

90 

85 

81 

76 

72 

67 

63 

59 

56 

61 

47 

43 

39 

36 

31 

28 

24 

21 

17 

70 

95 

90 

86 

81 

77 

72 

68 

64 

60 

66 

52 

48 

44 

40 

37 

33 

30 

26 

23 

20 

72 

95 

91 

86 

82 

78 

73 

69 

65 

61 

57 

63 

49 

46 

42 

39 

35 

32 

28 

25 

22 

74 

95 

91 

86 

82 

78 

74 

70 

66 

62 

58 

54 

61 

47 

44 

40 

37 

34 

30 

27 

24 

76 

96 

91 

87 

83 

78 

74 

70 

67 

63 

59 

56 

62 

48 

45 

42 

38 

35 

32 

29 

26 

78 

96 

91 

87 

83 

79 

75 

71 

67 

64 

60 

57 

53 

50 

46 

43 

40 

37 

34 

31 

28 

80 

96 

91 

87 

83 

79 

76 

72 

68 

64 

61 

57 

54 

51 

47 

44 

41 

38 

35 

32 

29 

82 

96 

91 

87 

83 

79 

76 

72 

69 

65 

62 

58 

55 

52 

49 

46 

43 

40 

37 

34 

31 

84 

96 

92 

88 

84 

80 

77 

73 

70 

66 

63 

69 

66 

63 

50 

47 

44 

41 

38 

35 

32 

86 

96 

92 

88 

84 

80 

77 

73 

70 

66 

63 

60 

67 

54 

51 

48 

45 

42 

39 

37 

35 

88 

96 

92 

88 

85 

81 

78 

74 

71 

67 

64 

61 

58 

56 

53 

49 

46 

43 

41 

39 

35 

90 

96 

92 

88 

85 

81 

78 

74 

71 

68 

64 

61 

58 

56 

53 

50 

47 

44 

42 

39 

37 

92 

96 

92 

89 

86 

82 

78 

76 

72 

69 

66 

62 

69 

57 

54 

61 

48 

46 

43 

40 

38 

94 

90 

92 

89 

86 

82 

78 

76 

72 

69 

66 

63 

60 

57 

54 

62 

49 

46 

44 

41 

39 

96 

96 

93 

89 

86 

82 

79 

76 

73 

70 

67 

64 

61 

58 

55 

63 

50 

47 

45 

42 

40 

98 

96 

93 

89 

86 

82 

79 

76 

73 

70 

67 

64 

61 

58 

56 

63 

51 

48 

46 

43 

41 

100 

96 

93 

90 

86 

83 

80 

77 

74 

71 

68 

65 

62 

69 

67 

64 

52 

49 

47 

44 

42 

74 


PHYSICAL  GEOGRAPHY  MANUAL 


TABLE  B   (continued) 


^2 

Difference  between  Readings  of  the  Dk\ 

AND  THE  Wet  Bulb 

«S 

21 

22 

23 

24 

25 

26 

27 

28 

29 

30 

31 

32 

33 

34 

35 

36 

37 

38 

39 

40 

60 

2 

62 

6 

2 

64 

9 

5 

2 

66 

11 

8 

6 

1 

68 

14 

11 

8 

4 

1 

70 

17 

13 

10 

7 

4 

1 

72 

19 

16 

13 

10 

7 

4 

1 

74 

21 

18 

15 

12 

9 

7 

4 

1 

76 

23 

20 

17 

14 

12 

9 

6 

4 

1 

78 

25 

22 

19 

16 

14 

11 

9 

6 

4 

1 

80 

27 

24 

21 

18 

16 

13 

11 

8 

6 

4 

1 

82 

28 

25 

23 

20 

18 

15 

13 

10 

8 

6 

4 

1 

84 

30 

27 

25 

22 

20 

17 

15 

12 

10 

8 

6 

4 

2 

86 

31 

29 

26 

24 

21 

19 

17 

14 

12 

10 

8 

6 

4 

2 

88 

33 

30 

28 

25 

23 

21 

18 

16 

14 

12 

10 

8 

6 

4 

2 

90 

34 

32 

29 

27 

24 

22 

20 

18 

16 

14 

12 

10 

8 

6 

4 

2 

92 

35 

34 

30 

28 

26 

24 

22 

19 

17 

15 

13 

11 

9 

8 

6 

4 

2 

94 

36 

34 

32 

29 

27 

25 

23 

21 

19 

17 

15 

13 

11 

9 

8 

6 

4 

2 

1 

96 

37 

35 

33 

31 

29 

26 

24 

22 

20 

18 

17 

15 

13 

11 

9 

7 

6 

4 

3 

1 

98 

39 

36 

34 

32 

30 

28 

26 

24 

22 

20 

18 

16 

14 

13 

11 

9 

7 

6 

4 

3 

100 

40 

37 

35 

33 

31 

29 

27 

25 

23 

21 

19 

18 

16 

14 

12 

11 

9 

7 

6 

4 

EXERCISE  XIV 


LIGHT 


Part  I 


Darken  the  laboratory,  allowing  only  a  single  beam  of  sun- 
light to  enter  through  a  very  small  aperture  made  for  the  pur- 
pose. Fill  with  water  a  glass  jar  with  straight  sides,  and  add 
a  little  soap  to  make  it  cloudy.  This  will  render  visible  the  path 
of  the  beam.  Use  a  mirror  and  direct  the  ray  of  light  so  that 
it  will  strike  the  surface  of  the  water  at  any  angle  other  than 
ninety  degrees.  Note  and  record  any  change  in  the  direction" 
of  the  path  of  the  beam  after  it  strikes  the  surface  of  the  water. 
This  change  of  direction  is  called  refraction.  Define  refraction. 
Draw  the  apparatus  and  show  the  path  of  the  beam  of  light,  so 


LIGHT  •  75 

as  to  illustrate  refraction.  Give  your  drawing  a  title.  When 
light  enters  any  transparent  substance  obliquely  from  the  air, 
this  substance  refracts  the  light. 

Pass  a  beam  of  light  through  a  triangular  glass  prism,  and 
let  the  refracted  light  fall  on  a  white  wall  or  on  a  screen  placed 
for  the  purpose.  Describe  what  you  see.  How  many  colors  can 
you  see?  Which  color  is  refracted  most?  Which  least?  This 
band  of  colors  is  called  the  spectrum.  Name  in  order  the  seven 
principal  colors  of  the  spectrum.  Stand  in  such  a  position  that 
your  eye  will  be  in  the  region  of  red  light.  What  color  can  you 
see?  Can  you  see  any  other  colors  from  this  position  without 
moving  the  prism  ?  What  becomes  of  the  colors  which  you  do 
not  see  ? 

Raindrops  refract  and  reflect  the  rays  of  the  sun,  thus  form- 
ing the  rainbow.  How  many  colors  does  any  one  raindrop  send 
forth?  How  many  of  these  colors  can  you  see  from  any  one 
raindrop  ?  What  becomes  of  those  which  you  do  not  see  ?  When 
the  sun  is  in  the  west,  in  which  direction  is  the  rainbow  seen  ? 
What  is  the  condition  of  the  sky  back  of  the  rainbow  ?  Name 
three  conditions  necessary  for  the  formation  of  a  rainbow. 
Compare  the  height  of  a  rainbow  which  is  seen  just  before  sun- 
set with  the  height  of  one  which  occurs  earlier  in  the  afternoon. 
Account  for  the  difference.  The  portion  of  the  rainbow  which 
is  visible  forms  an  arc  of  a  circle.  What  could  be  done  to  make 
the  whole  circle  visible  ? 

Part  II 

Cause  a  beam  of  sunlight  to  pass  horizontally  through  the 
glass  jar  filled  with  soapy  water.  Look  at  the  jar  from  the  side 
at  which  the  light  enters.  What  color  is  it?  Look  at  the  jar 
from  the  side  at  which  the  light  emerges.  What  color  is  it? 
What  color  of  light  passes  through  most  readily  ?  There  is  one 
color  of  the  spectrum  that  passes  readily  through  the  upper 
regions  of  the  atmosphere  and  goes  out  into  space,  suffering 
only  slight  change  in  its  direction.  What  color  do  you  think  it 
is  ?    Another  (with  those  colors  which  are  closely  related  to  it) 


76  PHYSICAL  GEOGEAPHY  MANUAL 

is  more  interfered  with,  diffused,  and  reflected,  until  that  is  the 
only  color  which  comes  from  the  open  sky  to  the  earth.  Which 
color  is  it  ?    Why  is  the  sky  blue  ? 

In  the  evening  and  early  morning  the  light  of  the  sun  must 
come  long  distances  through  the  earth's  atmosphere.  Why 
through  greater  distances  than  at  noon?  What  colors  of  light 
are  liable  to  "  get  tangled  up  "  in  the  atmosphere  before  reach- 
ing us?  Which  one  will  come  through  most  readily?  Which 
of  these  will  we  see?  What  color  would  this  make  the  sky 
appear  to  be  in  the  evening  and  early  in  the  morning?  Does 
this  accord  with  your  experience  ? 

EXERCISE  XV 

MAGNETISM 

Thrust  one  end  of  a  bar  magnet  into  a  box  of  tacks.  Remove 
it  and  make  a  drawing  of  what  you  see.  Place  one  end  of  the 
magnet  near,  but  not  touching,  one  end  of  the  needle  of  a  com- 
pass. What  occurs?  Repeat,  presenting  the  magnet  to  the  other 
end  of  the  magnetic  needle.  Does  it  affect  both  ends  of  the 
needle  alike?  Tie  a  string  to  the  middle  of  the  magnet,  suspend 
it,  and  let  it  come  to  rest.    (Select  a  string  that  will  not  twist,  or, 

instead  of  using  the  string, 

balance  the  magnet  on  two 

watch  crystals,  as  in  Fig.  2.) 

Fig.  2.    A  Bar  Magnet  mounted  on  Two    In  which    direction    does   it 

Watch  Crystals  so  as  to  swing  freely    come  to  rest?    Try  repeat- 

under  the  Influence  of  the  Earth's  Mag-    ^^^      ^nd    compare    results. 

netism  ,  .       ^ 

Ihe  earth  is  a  big  magnet 

and  acts  upon  your  bar  magnet  very  much  as  the  magnet 
did  upon  the  compass  needle.  Where  are  the  magnetic  poles 
of  the  earth  ?  (Refer  to  the  books,  and  give  latitude  and  longi- 
tude.) Upon  what  property  of  the  earth  does  the  compass 
depend?  When  was  the  compass  invented?  To  whom  is  it 
most  valuable  ?  How  did  the  invention  of  the  compass  hasten 
the  discovery  of  America? 


ISOTHERMS  77 

Compare  the  direction  of  the  magnetic  needle  with  your  north 
and  south  hne  (Exercise  V).  Does  the  needle  point  due  north? 
If  not,  does  it  point  east  or  west  of  due  north?  How  many 
degrees?  This  difference  measured  in  degrees  east  or  west  of 
due  north  is  called  inagnetic  declination.  Refer  to  the  map  which 
shows  magnetic  declination  in  the  United  States.  Determine 
and  record  the  magnetic  declination  at  the  following  points : 
Portland  (Me.),  Portland  (Ore.),  Los  Angeles,  Denver,  St.  Louis, 
Springfield  (O.),  Washington  (D.C.),  New  York  city.  Name 
the  states  through  which  the  line  of  no  declination  passes. 
Refer  to  the  pilot  chart  of  the  North  Atlantic  ocean  and  trace 
the  line  of  no  declination  (here  called  the  line  of  no  variation), 
naming  islands  near  which  it  passes  and  telling  where  it  strikes 
the  coast  of  South  America.  Refer  to  the  pilot  chart  of  the 
North  Pacific  ocean  and  locate  the  line  of  no  declination  (varia- 
tion). In  what  direction  does  the  compass  point  at  Manila,  P.I.? 
What  change  would  there  be  in  the  direction  of  the  compass 
in  sailing  along  the  great  circle  route  from  Yokohama  to 
San  Francisco? 

EXERCISE  XVI 

ISOTHERMS 

Part  I 

The  accompanying  table  gives  temperatures  as  reported  by 
the  United  States  Weather  Bureau  at  8  A.M.,  Thursday,  May  12, 
1904.  Use  a  fine-pointed  pen  and  insert  the  proper  figures  as 
near  as  possible  to  each  circle  representing  a  town.  Be  very 
careful  in  selecting  the  proper  circle  for  towns  in  the  eastern 
part  of  the  United  States.  Use  your  pencil  and  draw  the  iso- 
therm of  40  degrees,  beginning  at  Sault  Ste.  Marie,  Mich. 
Draw  the  line  toward  the  west,  leaving  north  of  the  line  all 
places  having  a  temperature  lower  than  40  degrees,  and  south 
of  the  line  all  places  having  a  temperature  higher  than  40 
degrees.    This  line  will  be  somewhat  irregular.    It  will  cross 


78  PHYSICAL  GEOGEAPHY  MANUAL 

into  British  Columbia.  Begin  with  Tacoma,  Wash.,  and  draw 
the  isotherm  of  50  degrees.  This  line  is  very  irregular  in  the 
eastern  states.  It  passes  through  Pittsburg,  Pa.,  to  Asheville, 
N.C.,  where  it  makes  a  sharp  curve,  passing  back  toward  the 
north  through  Wytheville,  Va.  Continue  it  through  eastern 
Pennsylvania  to  the  Atlantic  ocean  near  New  York  city. 
Begin  with  Norfolk,  Va.,  and  draw  the  isotherm  of  60  degrees. 
Begin  with  Jacksonville,  Fla.,  and  draw  the  isotherm  of  70 
'  degrees. 

After  your  teacher  approves  your  work,  trace  the  isotherms 
in  ink.  Continue  each  at  both  ends  about  half  an  inch  beyond 
the  boundary  of  the  country,  and  place  large  figures  to  indicate 
the  temperature  which  is  represented.  Give  your  map  an 
appropriate  title. 

Part  II 

Write  a  paper  in  which  you  answer  the  following  questions 
about  your  map.  In  what  region  do  the  isotherms  of  40,  50, 
and  60  degrees  reach  their  farthest  point  north  ?  Does  this  indi- 
cate that  this  region  is  warmer  or  colder  than  other  regions  in 
the  same  latitude?  (Determine  this  by  actual  reading  of  tem- 
peratures.) There  are  two  regions  where  these  three  isotherms 
make  great  bends  toward  the  south.  Does  this  indicate  that 
these  regions  are  warmer  or  colder  than  the  other  regions  in  the 
same  latitude  ?  (Determine  this  by  actual  reading  of  tempera- 
tures.) Give  names  to  these  regions.  Characterize  the  lay  of 
the  land  as  levels  gently  sloping,  hilly,  broken,  or  mountainous. 
Compare  the  elevation  of  the  two  regions  where  the  isotherms 
bend  far  south  with  the  elevation  of  the  lower  Mississippi,  Ohio, 
and  Missouri  valleys,  where  the  isotherms  bend  far  north.  (See 
the  map  of  the  United  States,  which  is  shaded  to  show  eleva- 
tions.) What  have  the  elevation  and  the  lay  of  the  land  to  do 
with  the  prevailing  temperature  of  a  region?  Take  an  imagi- 
nary trip  from  west  to  east  across  the  United  States,  along  the 
parallel  of  40  degrees  north  latitude.    Tell  between  what  degrees 


•S    S 


■B  3 

o     S 
►5    I 


2    % 


79 


80  PHYSICAL   GEOGEAPHY  MANUAL 

of  longitude  or  in  what  states  you  are  passing  from  a  warmer  to 
a  colder  region,  according  to  this  map ;  also  from  a  colder  to  a 
warmer  region. 

Paet  III 

It  should  be  borne  in  mind  that  the  map  which  you  have 
constructed  and  used  shows  the  conditions  of  temperature  as 
they  existed  on  one  day  only  at  a  particular  time  of  this  day. 
Figs.  3  and  4  are  isothermal  maps  made  by  averaging  tempera- 
tures for  an  entire  month  during  a  period  of  several  years.  In 
what  respects  are  these  maps  superior  to  yours  ? 

Refer  to  Fig.  3,  which  shows  the  isotherms  for  the  month 
of  July.  In  passing  from  the  sea  to  the  land  in  the  northern 
hemisphere  do  the  isotherms  bend  toward  the  north  or  toward 
the  south  ?  (Notice  the  marked  deflection  on  the  west  coast  of 
North  America.)  Does  this  indicate  that  the  land  is  warmer  or 
cooler  than  the  sea  ?    Account  for  the  difference  in  temperature. 

Refer  to  Fig.  4,  which  shows  the  isotherms  for  the  month  of 
January.  In  passing  from  the  sea  to  the  land  in  the  northern 
hemisphere  do  the  isotherms  bend  toward  the  north  or  toward 
the  south?  (Again  notice  the  marked  deflection  on  the  west 
coast  of  North  America.)  Does  this  indicate  that  the  land  is 
warmer  or  cooler  than  the  sea?  Account  for  the  difference  in 
temperature. 

In  what  part  of  the  world  do  you  find  the  highest  temperature 
in  July  ?  Is  this  on  the  land  or  on  the  sea  ?  In  what  part  of 
the  world  do  you  find  the  lowest  temperature  in  January?  Is 
this  on  the  sea  or  on  the  land  ? 


81 


82 


PHYSICAL  GEOGRAPHY  MANUAL 


TEMPERATURES  AT  VARIOUS  PLACES  IN  THE  UNITED   STATES 
At  8  A.M.,  Thursday,  May  12,   1904 


Albany,  N.Y 48 

New  York,  N.Y.  ...  48 

Scran  ton.  Pa 44 

Harrisburg,  Pa.  ...  52 
Philadelphia,  Pa.  .  .  62 
Atlantic  City,  N.J.  .  52 
Baltimore,  Md.  ...  54 
Washington,  D.C.  .  .  54 
Mount  Weather,  Va. .  50 
Lynchburg,  Va.  ...  64 
Richmond,  Va.    ...  50 

Norfolk,  Va 60 

Wytheville,  Va.  .  .  .  50 
Charlotte,  N.C.  ...  58 
Asheville,  N.C.    ...  50 

Raleigh,  N.C 60 

Hatteras,  N.C 64 

Wilmington,  N.C.  .  .  64 
Charleston,  S.C.  .  .  .  66 

Augusta,  Ga 60 

Savannah,  Ga 64 

Jacksonville,  Fla.    .  .  70 

Jupiter,  Fla 76 

Key  West,  Fla.    ...  78 

Atlanta,  Ga 62 

Macon,  Ga 62 

Tampa,  Fla 70 

Pensacola,  Fla.    ...  70 

Mobile,  Ala 62 

Montgomery,  Ala.  .  .  66 
Birmingham,  Ala.  .  .  64 
Meridian,  Miss.  ...  62 
Vicksburg,  Miss. .  .  .  62 
New  Orleans,  La.  .  .  66 
Shreveport,  La.  ...  62 
Little  Rock,  Ark.    .  .  62 

Palestine,  Tex 62 

Galveston,  Tex.  ...  72 
San  Antonio,  Tex. .  .  64 
Corpus  Christi,  Tex. .  72 
Memphis,  Tenn.  ...  64 
Nashville,  Tenn.  ...  66 


Chattanooga,  Tenn.  .  56 
Knoxville,  Tenn.     .  .  56 

Louisville,  Ky 62 

Lexington,  Ky.    ...  60 

Indianapolis,  Ind.  .  .  60 
Cincinnati,  Ohio ...  56 
Columbus,  Ohio  ...  54 
Elkins,  W.Va.  .....  42 

Parkersburg,  W.Va.    52 

Pittsburg,  Pa 50 

Parry  Sound,  Ont.  .  .  38 
Saugeen,  Ont.  .  .  .  .  50 
Syracuse,  N.Y.    ...  44 

Oswego,  N.Y 44 

Rochester,  N.Y.  .  .  .48 

Buffalo,  N.Y 48 

Erie,  Pa 52 

Cleveland,  Ohio  ...  52 
Toledo,  Ohio     ....  58 

Detroit,  Mich 56 

Alpena,  Mich 44 

SaultSte.  Marie,  Mich.  40 
Houghton,  Mich.  .  .  38 
Marquette,  Mich.  .  .  38 
Escanaba,  Mich.  ...  42 
Green  Bay,  Wis. ...  54 
Grand  Rapids,  Mich.  62 

Chicago,  111 62 

Duluth,  Minn 34 

St.  Paul,  Minn.  ...  44 
La  Crosse,  Wis.  ...  48 
Dubuque,  Iowa  ...  58 
Davenport,  Iowa ...  62 
Des  Moines,  Iowa  .  .  50 
Keokuk,  Iowa  ....  66 
Springfield,  111.    ...  64 

St.  Louis,  Mo 64 

Cairo,  111 62 

Kansas  City,  Mo.  .  .  62 
Wichita,  Kans.  ...  62 
Concordia,  Kans.  .  .  56 
Omaha,  Neb 50 


Valentine,  Neb.   ...  42 

Sioux  City,  Iowa    .  .  44 

Huron,  S.D 42 

Pierre,  S.D 46 

Moorhead,  Minn.    .  .  38 

Bismarck,  N.D.    ...  34 

Williston,  N.D.    ...  34 

Havre,  Mont 86 

Helena,  Mont 36 

Miles  City,  Mont.  .  .  36 

Kalispell,  Mont.  ...  34 

Pocatello,  Ida 38 

Bois^,  Ida 44 

Rapid  City,  S.D.    .  .  42 

Lander,  Wyo 38 

Salt  Lake  City,  Utah.  44 

Cheyenne,  Wyo.  ...  33 

North  Platte,  Neb. .  .  44 

Denver,  Col 40 

Amarillo,  Tex 56 

Pueblo,  Col 44 

Dodge,  Kans 60 

Oklahoma,  Okla.    .  .  62 

Abilene,  Tex 62 

El  Paso,  Tex 60 

Santa  F^,  N.M.    ...  42 

Flagstaff,  Ariz.    ...  42 

Yuma,  Ariz.  .....  62 

Phoenix,  Ariz 62 

Victoria,  B.C 54 

Kamloops,  B.C.   .  .  .  36 

Spokane,  Wash.  ...  42 

Tacoma,  Wash.    ...  50 

Portland,  Ore 64 

Roseburg,  Ore.    ...  48 

Baker  City,  Ore.     .  .  36 

Carson  City,  Nev.  .  .  44 

Eureka,  Cal 50 

Red  Bluff,  Cal.    ...  62 
San  Francisco,  Cal.   .  62 

Los  Angeles,  Cal.  .  .  52 

San  Diego,  Cal.   ...  56 


THE  BAROMETER  83 

EXERCISE  XVII 
THE  BAROMETER 

Aim.  To  ascertain  whether  the  pressure  of  the  atmosphere 
can  be  measured. 

Apparatus.  Two  glass  tubes,  each  closed  at  one  end,  one  18 
inches  long  and  one  32  inches  long ;  a  cup  and  mercury. 

Procedure.  Fill  the  18-inch  tube  and  invert  it  in  the  cup  of 
mercury.  What  happens?  Account  for  this.  Fill  the  32-inch 
tube  with  mercury  and  invert  it  in  the  cup  of  mercury.  What 
happens  ?  Account  for  this.  If  the  pressure  of  the  air  could  be 
increased,  how  would  the  length  of  the  column  of  mercury  be 
affected  ?  If  the  pressure  of  the  air  were  decreased,  how  would 
the  length  of  the  column  of  mercury  be  affected  ?  What  do  you 
know  of  air  pressure  at  high  altitudes  ?  How  would  the  mercury 
column  stand  at  high  altitudes  ?  How  high  is  the  average  mer- 
cury column  at  sea  level?  Make  a  drawing  showing  the  32-inch 
tube  inverted  in  the  cup  of  mercury. 

Conclusion.  Can  atmospheric  pressure  be  measured?  What 
name  is  given  to  the  instrument  used  for  this  purpose  ? 

EXERCISE  XVIII 

ISOBARS 

The  accompanying  table  gives  barometric  pressure  in  inches 
and  hundredths  at  various  places  in  the  United  States,  at  8  a.m., 
W^ednesday,  March  2,  1904.  Use  a  fine-pointed  pen  and  put 
the  figures  on  the  map  in  the  proper  places.  Place  the  figures 
so  that  the  circle  which  represents  a  town  shall  come  in  the 
place  of  the  decimal  point.  Find  the  place  having  the  lowest 
barometric  reading  and  write  there  the  word  Low.  Does  this 
mean  that  the  atmospheric  pressure  at  this  place  is  great  or 
small?  Draw  isobars  as  follows:  29.60,  beginning  at  Omaha, 
Neb.;  29.80,  beginning  at  Springfield,  Mo.;  30.00,  beginning  at 
Los  Angeles,  Cal.    Draw  also  isobars  of  30.10,  30.20,  and  30.30. 


84 


PHYSICAL  GEOGRAPHY  MANUAL 


These  will  extend  through  parts  of  the  Atlantic  and  Middle 
states.  They  will  also  extend  through  parts  of  California,  Oregon, 
and  Washington.  Do  not  draw  isobars  at  any  place  in  Canada 
or  Mexico  unless  there  are  figures  to  show  that  they  should  be 
so  drawn.  Finish  the  map  by  placing  large  figures  to  show 
pressure  at  the  ends  of  isobars  or  at  some  conspicuous  place  on 
the  isobars.    Give  your  map  a  title. 


BAROMETRIC  PRESSURE  IN  INCHES  AND  HUNDREDTHS 


At  8  A.M.,  Wednesday,  March  2,  1904 


Binghamton,  N.Y 30.32 

Albany,  N.Y 30.28 

New  York,  N.Y 30.30 

Scranton,  Pa 30.22 

Harrisburg,  Pa 30.28 

Philadelphia,  Pa.  ....     .  30.32 

Atlantic  City,  N.J 30.36 

Baltimore,  Md 30.30 

Washington,  D.C 30.32 

Lynchburg,  Va 30.26 

Richmond,  Va. 30.30 

Norfolk,  Va 30.30 

Wytheville,  Va 30.20 

Charlotte,  N.C 30.20 

Asheville,  N.C 30.14 

Raleigh,  N.C 30.24 

Hatteras,  N.C 30.22 

Wilmington,  N.C 30.20 

Charleston,  S.C 30.16 

Augusta,  Ga 30.14 

Savannah,  Ga 30.14 

Jacksonville,  Fla 30.16 

Jupiter,  Fla 30.18 

Key  West,  Fla 30.14 

Atlanta,  Ga 30.10 

Macon,  Ga 30.12 

Tampa,  Fla 30.18 

Pensacola,  Fla 30.16 

Mobile,  Ala 30.14 

Montgomery,  Ala 30.10 


Birmingham,  Ala 30.08 

Meridian,  Miss 30.08 

Vicksburg,  Miss 30.02 

New  Orleans,  La 30.12 

Shreveport,  La 29.96 

Fort  Smith,  Ark 29.82 

Little  Rock,  Ark 29.94 

Palestine,  Tex 29.96 

Galveston,  Tex 30.06 

Taylor,  Tex 29.92 

San  Antonio,  Tex 29.94 

Corpus  Christi,  Tex 29.98 

Memphis,  Tenn 29.98 

Nashville,  Tenn 30.06 

Knoxville,  Tenn 30. 10 

Lexington,  Ky 30.08 

Evansville,  Ind 29.98 

Indianapolis,  Ind 30.00 

Cincinnati,  Ohio 30.08 

Columbus,  Ohio 30.10 

Parkersburg,  W.Va.       .     .     .  30.14 

Pittsburg,  Pa 30.14 

White  River,  Ont.      ....  30.02 

Port  Arthur,  Ont 30.08 

Parry  Sound,  Ont 30.08 

Saugeen,  Ont 30.08 

Syracuse,  N.Y 30.20 

Oswego,  N.Y 30.18 

Rochester,  N.Y 30.14 

Buffalo,  N.Y 30.14 


ISOBARS 


85 


Erie,  Pa 30.14 

Cleveland,  Ohio 30.12 

Toledo,  Ohio 30.10 

Detroit,  Mich 30.10 

Alpena,  Mich 30.04 

Sault  Ste.  Marie,  Mich.       .     .  30.00 

Houghton,  Mich.  .....  30.02 

Marquette,  Mich 30.02 

Escanaba,  Mich 29.94 

Green  Bay,  Wis 29.90 

Grand  Rapids,  Mich.       .     .     .  30.00 

Milwaukee,  Wis 29.90 

Chicago,  111 29.94 

Dulutli,  Minn 29.94 

St.  Paul,  Minn 29.70 

La  Crosse,  Wis 29.76 

Dubuque,  Iowa 29.76 

Davenport,  Iowa 29.78 

Des  Moines,  Iowa      .     .     .     .  29.68 

Keokuk,  Iowa 29.86 

Springfield,  111 29.86 

St.  Louis,  Mo 29.88 

Cairo,  111 29.96 

Springfield,  Mo 29.80 

Kansas  City,  Mo 29.74 

Wichita,  Kans 29.66 

Concordia,  Kans 29.64 

Omaha,  Neb 29.60 

Valentine,  Neb 29.40 

Sioux  City,  Iowa 29.54 

Huron,  S.D 29.52 

Moorhead,  Minn 29.88 

Bismarck,  N.D 30.00 

Williston,  N.D 30.06 

Battlefo'rd,  Sask 30.30 

Havre,  Mont 30.26 

Helena,  Mont 30.08 

Yellowstone  Park,  Wyo.     .     .  29.68 

Miles  City,  Mont 30.16 


Kalispell,  Mont 30.04 

Lewiston,  Ida 30.16 

Pocatello,  Ida 29.86 

Bois^,  Ida 30.14 

Rapid  City,  S.D 29.74 

Lander,  Wyo 29.46 

Salt  Lake  City,  Utah      .     .     .  29.70 

Modena,  Utah 29.92 

Grand  Junction,  Col.      .     .     .  29.80 

Cheyenne,  Wyo 29.50 

North  Platte,  Neb 29.56 

Denver,  Col 29.46 

Amarillo,  Tex 29.72 

Pueblo,  Col 29.56 

Dodge,  Kans 29.68 

Oklahoma,  Okla 29.66 

Fort  Worth,  Tex 29.86 

Abilene,  Tex 29.80 

El  Paso,  Tex 29.90 

Santa  F^,  N.M 29.92 

Flagstaff,  Ariz 30.02 

Yuma,  Ariz 29.94 

Phoenix,  Ariz 29.96 

Victoria,  B.C 30.30 

Kamloops,  B.C 30.28 

Spokane,  Wash 30.18 

Walla  Walla,  Wash 30.28 

Tacoma,  Wash 30.32 

Portland,  Ore 30.32 

Roseburg,  Ore 30.26 

Baker  City,  Ore 30.22 

Carson  City,  Nev 29.82 

Winnemucca,  Nev 29.88 

Red  Bluff,  Cal 30.08 

San  Francisco,  Cal 30.12 

Fresno,  Cal 30.12 

Los  Angeles,  Cal 30,00 

San  Diego,  Cal 29.96 


86 


PHYSICAL  GEOGRAPHY  MANUAL 


EXERCISE  XIX 
OBSERVATIONS  OF  THE  WEATHER 

Make  observations,  read  the  instruments,  refer  to  the  weather 
map,  and  fill  a  table  similar  to  the  accompanying  table.  Make 
this  record  each  day  for  one  month. 

In  filling  column  2,  let  O  represent  a  clear  sky,  #  cloudy, 
3  one  half  of  the  sky  overcast,  etc. 

In  columns  8  and  19  indicate  wind  direction  by  arrows.  A 
change  may  be  indicated  by  a  curve  or  by  a  sharp  turn. 

In  column  20  use  the  following  abbreviations :  C,  calm ; 
L,  light,  just  moving  the  leaves  of  trees,  or  blowing  the  smoke 
slowly  away  from  smokestacks ;  M,  moderate,  moving  small 
branches ;  B,  brisk,  swaying  branches,  blowing  up  dust ;  H,  high, 
blowing  up  twigs  from  the  ground,  swaying  whole  trees ;  G,  gale, 
breaking  small  branches,  blowing  down  shade  trees,  etc. 

In  column  22  give  quadrant,  or,  if  we  are  very  near  the 
center  of  the  area  of  low  pressure,  write  low. 

In  column  23  name  the  state  in  which  the  area  is  central. 

In  column  25  give  miles  per  day. 

In  column  26  name  the  region  of  the  United  States,  as  "  Lake 
region,"  "  eastern  Gulf  states,"  etc. 


1 

2 

3 

4 

5 

6 

7 

8 

9 

10 

11 

12 

13 

14 

15 

16 

17 

18 

19 

20 

21 

22 

23 

24 

25 

26 

Date 

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PKEV AILING  WINDS  87 

EXERCISE  XX 
PREVAILING  WINDS 

Observe  the  pilot  chart  of  the  North  Atlantic  ocean.  How 
is  wind  direction  indicated?  (See  explanation  near  the  lower 
left-hand  corner  of  the  chart.)  How  is  the  percentage  of  calm 
days  in  any  region  indicated  ? 

From  what  direction  are  the  prevailing  winds  from  10  to  20 
degrees  north  latitude?  What  name  is  given  to  these  winds? 
(See  the  name  printed  in  blue  at  both  the  northern  and  the 
southern  limits  of  these  winds.)  From  what  direction  are  the 
prevailing  winds  from  the  equator  to  the  parallel  of  5  degrees 
north  latitude,  during  the  summer  months?  What  name  is 
given  to  these  winds?  Compare  the  percentage  of  calm  days 
in  the  region  where  these  two  winds  meet  with  the  number  in 
the  region  from  10  to  20  degrees  north  latitude.  What  name  is 
given  to  this  region  of  calms?  (See  the  text-books.)  At  what 
time  of  the  year  is  this  region  of  calms  farthest  north?  farthest 
south?  Where  does  the  north  limit  of  northeast  trades  strike 
the  United  States  in  December?   in  March?   in  September? 

Trace  with  a  pointer  an  irregular  line  from  the  Bermudas 
(65  degrees  west,  32  degrees  north)  to  the  Azores  (28  degrees 
west,  38  degrees  north),  passing  through  the  points  having  the 
highest  percentage  of  calm  days.  Give  the  date  of  the  map 
used  in  tracing  this  line.  Describe  the  general  direction  of  this 
line  from  the  former  point  to  the  latter.  Compare  with  the 
line  of  the  northern  limit  of  northeast  trades.  What  name  is 
given  to  this  region  of  calms?  From  what  direction  are  the 
prevailing  winds  from  15  to  20  degrees  north  of  this  region  of 
calms?  How  far  north  could  you  go,  according  to  this  map, 
and  still  find  the  same  winds  ? 

Why  is  there  a  difference  between  the  route  of  sailing  vessels 
bound  from  New  York  to  the  equator  and  sailing  vessels  bound 
from  the  equator  to  New  York  ? 

Observe  the  chart  for  the  North  Pacific.  What  kind  of  a  line 
is  that  portion  of  the  sailing  route  which  is  represented  from 


88  PHYSICAL  GEOGRAPHY  MANUAL 

San  Francisco  to  Australia?  from  Australia  to  San  Francisco 
by  way  of  the  western  passage  ?  Why  is  there  this  difference  ? 
Why  do  sailing  vessels  from  San  Diego  to  the  strait  of  Juan  da 
Fuca  put  out  to  sea  so  far  before  turning  north  ?  Give  latitude 
of  northeast  trades  in  the  Pacific  ocean  from  June  to  Septem- 
ber ;  from  December  to  March.    Account  for  the  difference. 


EXERCISE  XXI 
WINDS  m  A  CYCLONE 

Draw  a  rectangle  six  inches  long  and  an  inch  and  a  half 
wide.  Divide  this  into  four  squares  and  write  the  word  Low  in 
the  center  of  each. 

Observe  the  United  States  weather  maps.  The  arrows  indicate 
the  direction  of  the  wind.  Observe  the  map  for  March  6,  1904. 
What  is  the  direction  of  the  wind  in  the  northeast  quadrant? 
Observe  the  arrows  nearest  the  center  of  the  area  of  low  ba- 
rometer. What  is  the  direction  of  the  wind  in  the  northwest 
quadrant?  in  the  southwest  quadrant?  in  the  southeast  quad- 
rant ?  In  the  first  of  your  squares  put  at  least  four  arrows  to 
show  the  direction  of  the  wind  about  the  area  of  low  barometer. 
Under  this  square  write  the  date.  Observe  the  weather  maps 
for  the  following  dates  and  fill  in  the  other  squares  as  you  did 
the  first  one:  March  7,  1904;  March  19,  1904;  March  30, 
1904.  Give  your  completed  work  the  title;  "Direction  of  the 
winds  about  areas  of  low  pressure,  taken  from  the  United  States 
Weather  Map." 

Answer  the  following  questions.  What  is  the  shape  of  the 
path  of  the  winds  near  an  area  of  low  pressure  ?  Do  the  winds 
in  their  movements  seem  to  be  approaching  the  center  of  the 
area  of  low  pressure  or  constantly  getting  farther  away  ?  Does 
this  indicate  that  the  column  of  air  at  the  center  is  ascending 
or  descending  ?    Why  does  this  column  of  air  move  in  this  way  ? 

Draw  four  more  squares  and  put  the  word  High  in  the  center 
of  each.    Observe  the  weather  maps  for  the  following  dates  and 


AREAS  OF  PRECIPITATION  89 

place  arrows  to  indicate  the  directions  of  the  wind:  March  4, 
1904  ;  March  5,  1904  ;  March  7, 1904  ;  March  29, 1904.  What 
is  the  shape  of  the  path  of  the  winds  near  an  area  of  high  pres- 
sure ?  Do  the  winds  in  their  movements  seem  to  be  approach- 
ing the  center  of  the  area  of  high  pressure  or  constantly  getting 
farther  away?  Does  this  indicate  that  the  column  of  air  is 
ascending  or  descending?  Why  does  this  colunm  of  air  move 
in  this  way? 

Characterize  the  movement  of  the  winds  about  an  area  of  low 
pressure  as  clockwise  or  counter-clockivise.  Account  for  the  direc- 
tion of  this  movement.  What  name  do  the  books  give  to  such 
a  movement  of  the  winds?  Refer  to  any  one  of  the  maps  on 
which  a  distinct  low  barometer  is  indicated,  and  measure  the 
distance  in  miles  across  the  region  whose  winds  are  influenced 
by  the  low  pressure,  that  is,  the  region  in  which  the  majority  of 
the  arrows  indicate  that  the  wind  is  blowing  in  the  general 
direction  given  above.  Tell  the  date  of  the  map  from  which 
you  take  your  measurements.  Characterize  the  movement  of  the 
winds  about  an  area  of  high  pressure  as  clockwise  or  counter- 
clockwise. Account  for  the  direction  of  this  movement.  What 
name  do  the  books  give  to  such  a  movement  of  the  winds  ? 


EXERCISE  XXn 
AREAS  OF  PRECIPITATION 

When  a  mass  of  air  rises,  does  the  pressure  upon  it  increase 
or  decrease  ?  Why  ?  What  change  of  volume  does  this  produce  ? 
What  change  of  temperature  ?  What  effect  will  this  have  on 
its  capacity  for  water  vapor  ?  If  it  was  nearly  saturated  when 
it  began  to  rise,  what  will  probably  result  from  its  rising?  In 
which  do  you  think  you  would  find  greater  rainfall,  a  cyclone 
or  an  anticyclone  ? 

Refer  to  the  weather  maps  of  the  following  dates :  March  7, 
11,  16,  19,  29,  31,  in  the  year  1904.  Record  the  number  of 
cases  in  which  the  region  of  precipitation  coincides  with  the 


90 


PHYSICAL  GEOGRAPHY  MANUAL 


area  of  low  pressure.  Record  the  number  in  wliicli  it  does  not 
coincide,  but  is  nearer  the  area  of  low  pressure  than  it  is  to  the 
area  of  high  pressure.  Record  the  number  in  which  the  region 
of  rainfall  is  nearer  the  area  of  high  pressure  than  it  is  to  the 
area  of  low  pressure.  Do  these  observations  justify  your  answers 
in  the  preceding  paragraph  ? 


EXERCISE  XXIII 
TEMPERATURES  IN   CYCLONES  AND  ANTICYCLONES 

Examine  the  weather  map  for  Thursday,  March  3,  1904. 
What  is  the  temperature  represented  by  the  isotherm  passing 
nearest  the  center  of  the  area  of  low  pressure?  by  the  iso- 
therm passing  nearest  the  center  of  the  area  of  high  pressure  ? 

Which  has  the  higher  temperature,  the  area  of  high  pressure 
or  the  area  of  low  pressure  ?  What  reason  can  you  assign  for 
this?  What  has  been  the  change  of  temperature  during  the 
last  twenty-four  hours  near  the  area  of  low  pressure  ?  (Note 
the  more  or  less  circular  area  inclosed  by  the  line  of  red 
dots.  Read  words  and  figures  in  red,  and  record  the  number 
of  degrees  colder  or  degrees  warmer.)  What  has  been  the 
change  of  temperature  near  the  area  of  high  pressure  during 
the  same  time? 

Examine  maps  for  March  2,  3,  4, 11, 16, 19,  in  the  year  1904, 
and  tabulate  the  results  of  your  observations  according  to  the 
accompanying  form : 


Date 

Temperature 

Which 

IS  Warmer, 

Low  OR  High? 

Change  of  Temperature 
IN  the  last  24  Hours 

At  low 

At  high 

Near  low 

Near  high 

MOVEMENTS  OF  LOW  BAROMETER  91 

EXERCISE  XXIV 
MOVEMENTS  OF  LOW  BAROMETER  IN  THE  UNITED  STATES 

You  have  drawn  the  isobars  for  Wednesday,  March  2,  1904 
(Exercise  XVIII).  At  what  point  was  the  center  of  the  area  of 
low  pressure  for  that  day?  Where  is  the  center  of  the  area  of 
low  pressure  on  the  map  for  March  3  ?  In  what  direction  is  it 
from  that  of  March  2  ?  The  long  line  of  arrows  on  the  map  of 
^larch  3  traces  the  path  of  this  storm  center.  At  Valentine,  Neb., 
a  small  figure  2  placed  above  the  circle  indicates  that  the  storm 
was  central  there  on  the  second  day  of  the  nonth,  and  the  letters 
A.M.  just  below  the  circle  indicate  that  it  was  present  in  the  fore- 
noon of  that  day.  Where  was  the  storm  center  in  the  afternoon 
of  that  day?  Where  was  this  storm  firet  observed?  (Note  the 
fii-st  of  the  small  figures.)  On  what  day  was  it  first  observed  ? 
At  what  time  of  day?  Can  you  find  any  traces  of  this  storm  on 
the  map  for  March  4  ?    If  so,  where  ? 

How  many  miles  did  the  storm  move  from  the  morning  of 
March  1  to  the  morning  of  March  2?  How  far  did  it  move 
from  March  2  to  March  3  ?  How  far  from  March  3  to  March  4  ? 
What  is  the  average  rate  in  miles  per  day?  Find  the  average 
rate  in  miles  per  day  for  the  storm  marked  on  the  map  of 
March  11.  Do  the  same  for  the  maps  of  March  16  and  19. 
Find  the  average  rate  in  miles  per  day  for  these  four  storms. 
Near  what  point  do  the  majority  of  these  storms  first  reach  the 
United  States?  In  what  direction  do  they  move  across  the 
United  States  ?  Refer  to  the  pilot  charts  of  the  North  Atlantic 
ocean  and  observe  the  average  path  taken  by  storms  after  they 
leave  the  United  States.  Refer  to  the  pilot  charts  of  the  North 
Pacific  ocean  and  determine  the  average  path  of  storms  across 
the  Pacific  ocean  before  they  reach  the  United  States. 

Use  the  blank  weather  map  and  trace  the  paths  of  storms  for 
March  3,  11,  16,  and  19,  in  the  year  1904.  Mark  the  dates  of 
each  storm  track  as  they  are  marked  on  the  weather  map.  Give 
your  map  a  title.    The  following  title  is  suggested :  "  Map  of 


92  PHYSICAL  GEOGRAPHY  MANUAL 

the  paths  of  low  barometer  across  the  United  States,  taken 
from  United  States  weather  maps  for  March  3,  11,  16,  and  19, 
in  the  year  1904." 

EXERCISE  XXV 
WEATHER  FORECASTING 

Suppose  an  area  of  low  pressure  is  approaching  your  home 
from  the  southwest.  From  which  direction  is  the  wind  blowing 
at  your  home  ?  Is  the  barometer  rising  or  falling  ?  What  change 
in  temperature  will  probably  occur?  What  change  in  condition 
of  cloudiness?  Suppose  an  area  of  low  pressure  is  receding 
toward  the  northeast.  From  which  direction  is  the  wind  blow- 
ing at  your  home  ?  Is  the  barometer  rising  or  falling  ?  What 
change  in  temperature  will  probably  occur?  What  change  in 
condition  of  cloudiness  ? 

Suppose  that  on  Monday  at  your  home  the  wind  is  blowing 
from  the  southeast  and  the  barometer  is  falling.  In  which  direc- 
tion from  you  is  the  area  of  low  pressure?  Suppose  that  on 
Tuesday  the  wind  is  blowing  from  the  south  and  the  barometer 
is  low.  In  which  direction  from  you  is  the  center  of  the  storm? 
Suppose  that  on  Wednesday  the  wind  is  blowing  from  the  west, 
the  barometer  is  high,  and  the  temperature  is  low.  In  which 
direction  from  you  is  the  area  of  low  pressure  ?  Read  the  para- 
graph printed  in  red  on  the  Washington  weather  map.  Copy 
that  portion  which  applies  to  the  conditions  supposed  above  for 
Monday,  Tuesday,  and  Wednesday,  and  tell  the  source  of  the 
quotation. 

Observe  the  local  weather  map  without  reading  the  forecast. 
Using  all  that  you  have  learned  on  the  subject,  make  a  forecast 
for  your  locality  for  the  next  twenty-four  hours.  Compare  this 
with  the  Weather  Bureau  predictions  and  record  the  difference, 
if  any.  After  twenty-four  hours  compare  both  forecasts  with 
the  actual  conditions  of  the  weather  and  record  results. 


RAINFALL  93 

EXERCISE  XXVI 

RAINFALL 

Part  I 

The  accompanying  table  gives  the  average  annual  rainfall 
in  inches  for  a  period  of  twenty  years  at  various  places  in  the 
United  States.  Use  the  outline  map  of  the  United  States  and 
place  the  figures,  in  ink,  as  near  as  possible  to  the  circles  rep- 
resenting the  proper  towns.  Draw  isohyetah  (lines  connecting 
points  having  equal  annual  rainfall)  of  10,  20,  30,  40,  50,  and 
100  inches.  Shade  with  blue  the  various  belts,  making  the 
intensity  of  shading  somewhat  proportional  to  the  depth  of 
rainfall  represented.  Thus  the  regions  of  great  rainfall  will 
be  dark  blue,  and '  the  regions  of  least  rainfall  will  be  left 
unshaded. 

Part  II 

Write  a  paper  in  which  you  answer  the  following  questions. 
In  what  part  of  the  United  States  do  you  find  the  heaviest 
rainfall  ?  Why  is  the  rainfall  so  heavy  in  this  region  ?  (See 
Exercises  XX  and  XXIV.)  Why  is  the  rainfall  not  so  great  in 
western  Nebraska? 

Refer  to  Fig.  5.  Compare  the  rainfall  of  Chile  with  that  of 
Argentina.  What  winds  prevail  in  these  countries?  What  has 
this  to  do  with  the  difference  in  rainfall?  What  has  the  lay 
of  the  land  to  do  with  the  difference  in  rainfall?  What  parts 
of  the  world  have  the  heaviest  rainfall  ?  Compare  the  amount  of 
rainfall  along  the  equator  with  that  about  the  tropics. 

What  is  the  movement  of  the  winds  in  equatorial  regions? 
(See  Exercise  XX.)  What  has  this  to  do  with  excessive  rain- 
fall? Characterize  the  rainfall  as  great  or  small  in  the  regions 
of  northeast  and  southeast  trades.  Is  the  capacity  for  water 
vapor  increasing  or  decreasing  in  the  region  of  the  trade  winds  ? 
Explain. 


94 


RAINFALL 


95 


AVERAGE   ANNUAL   RAINFALL   IN  THE   UNITED   STATES 


Father  Point,  Que.    .  33 

Eastport,  Me 44 

Northfield,  Vt 34 

Portland,  Me 43 

Concord,  X.H 40 

Boston,  Mass 45 

Providence,  R.I.  ...  46 

Albany,  N.Y 39 

New  York,  N.Y.  ...  45 
Harrisburg,  Pa.  ...  42 
Philadelphia,  Pa.  .  .  42 
Washington,  D.C.  .  .  44 
Richmond,  Va.    ...  44 

Norfolk,  Va 50 

Wytheville,  Va.  .  .  .  42 
Charlotte,  N.C.    ...  50 

Raleigh,  N.C 49 

Hatteras,  N.C 63 

Wilmington,  N.C.  .  .  52 
Charleston,  S.C.  .  .  .  49 

Augusta,  Ga 48 

Savannah,  Ga 50 

Jacksonville,  Fla.  .  .  53 

Jupiter,  Fla 60 

Key  West,  Fla.    ...  38 

Atlanta,  Ga 52 

Tampa,  Fla 53 

Pensacola,  Fla.    ...  58 

Mobile,  Ala 63 

Montgomery,  Ala.  .  .  52 
Meridian,  Miss.  ...  68 
Vicksburg,  Miss.  .  .  53 
New  Orleans,  La.  .  .  56 
Shreveport,  La.  ...  47 
Fort  Smith,  Ark.  .  .  41 
Little  Rock,  Ark.  .  .  51 
Palestine,  Tex.  ...  44 
Galveston,  Tex.  ...  48 
San  Antonio,  Tex.  .  28 
Corpus  Christi,  Tex.  .  26 
Memphis,  Tenn.  ...  51 
Nashville,  Tenn.  ...  49 
Chattanooga,  Tenn.  .  53 
Knoxville,  Tenn.    .  .  60 


Louisville,  Ky 45 

Indianapolis,  Ind.  .  .  42 
Cincinnati,  Ohio  ...  41 
Columbus,  Ohio  ...  38 
Parkersburg,  W.Va.    43 

Pittsburg,  Pa 36 

White  River,  Ont.  .  .  25 
Port  Arthur,  Ont.  .  .  .25 
Parry  Sound,  Ont. .  .  38 

Saugeen,  Ont 34 

Oswego,  N.Y 37 

Buffalo,  N.Y 38 

Cleveland,  Ohio  ...  36 

Detroit,  Mich 32 

Alpena,  Mich 34 

SaultSte.Marie,Mich.  36 
Marquette,  Mich.  .  .  32 
Green  Bay,  Wis.  .  .  31 
Milwaukee,  Wis.     .  .  31 

Chicago,  111 34 

Duluth,  Minn 30 

St.  Paul,  Minn.  ...  29 
La  Crosse,  Wis.  ...  31 
Charles  City,  Iowa  .  29 
Dubuque,  Iowa  ...  34 
Davenport,  Iowa ...  33 
Des  Moines,  Iowa  .  .  32 
Keokuk,  Iowa  ....  35 
Springfield,  111.    ...  38 

St.  Louis,  Mo 41 

Cairo,  111 42 

Springfield,  Mo.  ...  44 
Kansas  City,  Mo.  .  .  36 
WichiU,  Kans.    ...  30 

Omaha,  Neb 30 

Valentine,  Neb.  ...  20 
Sioux  City,  Iowa  ...  26 

Huron,  S.D 21 

Pierre,  S.D 17 

Moorhead,  Minn.  .  .  24 
Bismarck,  N.D.  ...  18 
Williston,  N.D.  ...  14 
Battleford,  Sask.  .  .  14 
Havre,  Mont 14 


Helena,  Mont 16 

Miles  City,  Mont.   .  .  13 

Lewiston,  Ida 17 

Pocatello,  Ida 13 

Bois^,  Ida 14 

Rapid  City,  S.D.    .  .  16 

Lander,  Wyo 13 

Salt  Lake  City,  Utah  17 
Modena,  Utah  ....  7 
Grand  Junction,  Col.     8 

Durango,  Col 17 

Cheyenne,  Wyo. ...  13 
North  Platte,  Neb. .  .  18 

Denver,  Col 14 

Amarillo,  Tex 22 

Pueblo,  Col 12 

Dodge,  Kans 21 

Fort  Worth,  Tex.  .  .  34 

Abilene,  Tex 24 

Roswell,  N.M 18 

Santa  F^,  N.M.  ...  15 
Flagstaff,  Ariz.    ...  24 

Yuma,  Ariz 3 

Phoenix,  Ariz 7 

Victoria,  B.C 38 

Neah  Bay,  Wash.  .  112 
Spokane,  Wash.  ...  18 
Walla  Walla,  Wash.  .  17 
Tacoma,  Wash.    ...  62 

Portland,  Ore 46 

Glenora,  Ore.  ...  136 
Roseburg,  Ore.  ...  35 
Baker  City,  Ore. ...  20 
Carson  City,  Nev.  .  .  12 
Winnemucca,  Nev.    .     9 

Eureka,  Cal 46 

Red  Bluff,  Cal.  ...  24 
Sacramento,  Cal.  .  .  20 
San  Francisco,  Cal.  .  23 

Fresno,  Cal 9 

Independence,  Cal.  .  6 
San  Luis  Obispo,  Cal.  21 
Los  Angeles,  Cal.  .  .  16 
San  Diego,  Cal.    .  .  .     9 


96  PHYSICAL  GEOGKAPHY  MANUAL 

EXERCISE  XXVII 

ZONES  OF  CLIMATE 

Part  I 

What  is  meant  by  the  heat  equator?  Where  does  it  reach  its 
farthest  point  north  in  July  ?  (Refer  to  Fig.  3.)  Where  does  it 
reach  its  farthest  point  south  in  July?  About  what  is  its  aver- 
age latitude  for  this  month?  Where  does  it  reach  its  farthest 
point  south  in  January?  (Refer  to  Fig.  4.)  Where  does  it 
reach  its  farthest  point  north  in  January?  About  what  is  its 
average  latitude  for  this  month?  Is  the  heat  equator  farther 
from  the  geographical  equator  in  July  or  in  January  ?  Account 
for  the  difference. 

Professor  Davis  says  :  "  At  the  head  of  the  Gulf  of  Guinea, 
west  equatorial  Africa,  rain  is  most  abundant  in  March  and 
from  October  to  November.  In  Ceylon  the  rainfall  is  greater 
in  May  and  October  than  in  any  other  months ;  at  the  city  of 
Quito,  Ecuador,  in  April  and  November."  How  do  you  explain 
these  double  rainy  seasons  ? 

Part  II 

What  is  meant  by  range  of  temperature?  Refer  to  Fig.  6 
and  answer  the  following  questions. 

What  point  on  the  earth  has  the  greatest  range  of  tempera- 
ture? What  point  ranks  next?  Are  these  points  on  sea  or 
land?  Are  they  densely  or  sparsely  populated?  What  places 
have  least  range  of  temperature?  Do  any  densely  populated 
countries  lie  within  this  belt?  Which  is  more  desimble  for 
residence,  other  things  being  equal,  great  or  small  range  of 
temperature?  How  does  climate  help  to  make  men  indus- 
trious ? 

What  are  the  points  of  greatest  range  of  temperature  in  the 
southern  hemisphere  ?  Compare  these  ranges  with  those  of  the 
northern  hemisphere  and  account  for  the  difference.  If  the  earth's 


ZONES   OF  CLIMAJE 


97 


surface  were  all  land,  where  would  be  the  points  of  greatest 
range  of  temperature  ?  Why  are  the  points  of  greatest  range  in 
the  northern  hemisphere  not  located  farther  north  ? 


Fig.  6.  Lines  of  Equal  Annual  Range  of  Temperature 


Part  III 

Compare  tlie  east  and  the  west  coasts  of  the  United  States  in 
range  of  temperature  (e.g.  San  Francisco,  Cal.,  and  Norfolk,  Va. ; 
or  Portland,  Ore.,  and  Eastport,  Me.).  How  do  you  account  for 
the  difference?  (See  Exercise  XX.)  Make  similar  comparison 
of  the  east  and  the  west  coasts  of  Eurasia  (e.g.  Norway  and 
Kamchatka).  Compare  the  east  coast  of  North  America  and 
the  west  coast  of  Eurasia  (e.g.  Labrador  and  England). 


Part  IV 

Where  is  the  belt  of  tropical  calms  in  the  northern  hemi- 
sphere? (See  Exercise  XX.)  Is  this  a  region  of  high  or  low 
barometric  pressure  ?  (See  the  small  maps  on  the  pilot  charts.) 
Are  conditions  here  favorable  for  large  rainfall  ?  (See  Exercise 
XXII.)  Why  ?  How  is  this  region  of  calms  related  to  the  arid 
regions  of  the  southwestern  United  States  ?    In  what-  countries 


98  PHYSICAL   GEOGRAPHY  MANUAL 

of  the  eastern  hemisphere  do  you  find  extensive  deserts?  In 
what  latitude  are  they  ?  Compare  this  with  the  latitude  of  the 
region  of  calms.  Do  you  find  deserts  in  the  southern  hemisphere 
corresponding  to  the  region  of  tropical  calms  ? 

Southern  California  is  alternately  in  the  belt  of  tropical  calms 
and  the  region  of  prevailing  westerlies.  During  what  time  of 
year  is  it  in  the  belt  of  calms  ?  What  kind  of  weather  would 
you  expect  in  this  region  at  this  time  ? 

Give  all  the  reasons  that  you  can  for  the  marked  difference 
between  the  rainfall  on  the  coast  of  southern  California  and  that 
on  the  coast  of  Oregon. 

EXERCISE  XXVIII 

ELEVATIONS  AND  DEPRESSIONS  OF  THE  EARTH'S  SUR- 
FACE DRAWN  TO  SCALE 

Refer  to  the  map  of  the  United  States  showing  elevations  by 
colors  (Fig.  7).'  Use  cross-section  paper  and  draw  a  profile  along 
the  parallel  of  37  degrees  north  latitude.  Use  a  horizontal  scale 
of  2  millimeters  to  1  degree,  vertical  scale  of  2  millimeters  to 
1000  feet.  Draw  a  rectangle  around  your  profile,  marking  the 
degrees  above  and  the  elevations  on  the  right  and  left.  Indicate 
longitude  as  either  east  or  west.  Below  the  rectangle  write  the 
names  of  the  principal  land  and  water  features,  such  as  Pacific 
Ocean,  Coast  Mange,  Valley  of  California,  Sierra  Nevada  Moun- 
tains, Great  Basin,  etc.  Number  these  features  consecutively 
and  place  corresponding  figures  beneath  the  proper  part  of  the 
profile.  Give  your  profile  an  appropriate  title,  stating  horizontal 
and  vertical  scales. 

Note.  Use  pen  and  ink  to  finish  drawing.  The  water  may  be  colored 
a  very  light  blue.  The  land  may  be  shaded  with  a  lead  pencil.  Space 
above  land  and  water  should  be  left  without  shading. 


from  90  Greenwich  85 


CONTOUK  LINES  99 

EXERCISE  XXIX 

CONTOUR  LINES 

Part  I 

Shape  a  sand  hill  on  the  table  so  that  you  will  have  a  ridge 
extending  in  one  direction  from  the  summit,  and  one  or  more 
small  streams  flowing  down  the  sides.  Place  a  block  one  inch 
thick  on  the  table  and  lay  a  long  straight  pointer  on  top  of  it. 
Move  the  block  and  pointer  so  that  the  end  of  the  pointer  will 
just  touch  and  make  a  mark  on  the  side  of  the  hill.  Move  the 
block  and  pointer  around  so  that  a  continuous  line  will  be 
traced.  This  is  a  contour  line.  Place  another  block  under  the 
first,  so  that  the  pointer  will  be  two  inches  from  the  top  of 
the  table,  and  trace  another  line  around  the  hill.  Repeat  the 
process,  adding  one  block  at  a  time,  until  the  top  of  the  hill 
is  reached. 

Draw  a  map  of  the  surface  as  you  would  see  it  looking  from 
above.  Use  the  scale  most  convenient.  Give  your  map  a  title, 
stating  that  it  was  made  in  the  laboratory. 

Part  II 

Write  a  paper  as  follows  : 

Define  contour  line.  A  contour  interval  is  the  vertical  distance 
between  two  contour  lines.  What  is  the  contour  interval  in  the 
contour  map  of  the  sand  hill  ?  How  does  the  land  lie  where  the 
contour  lines  are  near  together?  where  they  are  far  apart? 
When  contour  lines  cross  a  stream  do  they  bend  up  the  stream 
or  down  the  stream  ?  When  contour  lines  pass  around  a  ridge 
do  they  bend  toward  the  summit  or  away  from  it? 

Part  III 

Answer  the  following  questions  by  referring  to  the  pic- 
ture, contour  map,  hachure  map,  and  profile  (Figs.  8-11).    After 


100 


PHYSICAL  GEOGRAPHY  MANUAL 


each  answer  put  in  parentheses  a  word  which  will  tell  from 
which  of  the  four  you  could  secure  the  desired  information. 
(1)  Give  height  of  cliff  at  A.  (2)  Determine  the  shortest  hori- 
zontal distance  from  A  to  the  sea.     (3)  How  many  streams  flow 


Fig.  8.    A  Landscape 


Fig.  9.  A  Hachure  Map  of  the  Region  shown  in  Fig.  8 

into  the  sea?  (4)  It  is  desired  to  make  a  road  in  a  straight 
line  from  B  to  0,  having  a  uniform  grade.  How  deep  will 
the  deepest  "cut"  be?  How  far  will  the  roadbed  be  above  the 
bed  of  the  large  stream  ?  (5)  In  which  direction  does  the  land 
slope  between  J.  and  B?  (6)  What  portion  of  this  region  is 
forested  ? 


CONTOUR  MAPS 


101 


From  which  of  these  sources  can  you  determine  vertical  dis- 
tances accurately?  horizontal  distances?  In  what  respects  is 
the  contour  map  superior  to  the  hachure  map  ?  In  what  respects 
is  the  picture  superior  to  either  ?    In  what  respects  is  it  inferior 

to  either? 

c 


Fig.  10.  A  Contour  Map  of  the  Region  shown  in  Fig.  8 


B\^ 


Fig.  11.    A  Profile  drawn  from  B  to  C  in  Fig.  10 


EXERCISE  XXX 

CONTOUR  MAPS 

Pakt  I 

Visit  a  small  stream  which  you  can  easily  walk  across.  Make 
a  map  of  the  region,  showing  the  stream,  its  tributaries,  the 
roads,  buildings,  and  other  prominent  landmarks.  Use  two 
parallel  lines  just  as  close  together  as  you  can  draw  them  to 
represent  the  roads.    Indicate  the  cardinal  points. 


102  PHYSICAL  GEOGRAPHY  MANUAL 

Walk  across  the  stream,  always  keeping  on  the  same  hori- 
zontal plane.  In  crossing,  do  you  go  up  the  stream  or  down 
the  stream?  Walk  for  a  considerable  distance,  always  keeping 
on  the  same  horizontal  plane.  Does  your  path  lead  you  from 
the  bed  of  the  stream  or  nearer  to  it  ?  Draw  a  line  on  the  map, 
tracing  the  path  along  which  you  have  walked.  This  is  a  con- 
tour line,  if  you  have  not  departed  from  a  horizontal  plane. 
Draw  other  contour  lines  both  above  and  below  this  one,  using 
a  contour  interval  of  10  feet. 

When  in  doubt  as  to  the  height  of  a  point,  walk  to  it  and 
compare  its  height  with  that  of  a  known  point.  Levels  may  be 
determined  by  the  use  of  the  clinometer.  Give  your  map  an 
appropriate  title,  saying  that  it  was  made  in  the  field. 

Part  II 

.  Refer  to  the  map.  Fig.  12.  Use  cross-section  paper  and  draw 
the  profile  along  an  imaginary  line  extending  from  A  to  B.  Use 
the  same  horizontal  scale  as  is  used  on  the  map ;  vertical  scale 
one  square  to  100  feet.  Make  a  rectangle  around  your  drawing 
and  put  figures  in  the  proper  places  to  indicate  elevations. 
Mark  the  ends  of  the  profile  with  letters  indicating  the  proper 
directions.  Give  your  drawing  a  title,  telling  from  what  kind 
of  map  it  is  made.    State  vertical  and  horizontal  scales. 

EXERCISE  XXXI 

THE  WEATHERING  OF  ROCKS 

Part  I 

Use  a  brass  ball  and  a  ring  which  is  just  large  enough  to  slip 
over  it  readily.  Heat  the  ball  in  the  flame  of  the  Bunsen  burner. 
Try  to  put  it  through  the  ring.  What  change  has  occurred? 
Account  for  this  change.  Let  the  ball  cool  and  try  again.  What 
change  do  you  observe  ?    What  effect  has  heat  upon  brass  ? 

Use  the  apparatus  consisting  of  a  freely  moving  lever,  with  a 
tense  rubber  string  on  the  long  arm  and  an  iron  wire  on  the 


w 


103 


104 


PHYSICAL  GEOGRAPHY  MANUAL 


other.  (See  Fig.  13.)  Heat  a  portion  of  the  wire  by  burning  a 
match  under  it.  What  effect  has  heat  upon  iron  ?  How  do  iron 
and  brass  act  upon  cooling  ? 

What  effect  do  you  suppose  heat  would  have  upon  a  rock  ? 
How  would  a  rock  probably  act  upon  cooling  ?  Do  rocks  exposed 
on  hillsides  suffer  change  of  temperature  ?    How  warm  do  rocks 


Fig.  13.   Apparatus  for  showing  the  Effect  of  Heat  on  Iron 

Apply  a  match  below  the  wire  at  A  and  observe  the 
movement  of  the  lever  at  B 

become  when  subjected  to  the  heat  of  the  sun  during  midsum- 
mer? Do  you  think  the  change  of  temperature  from  summer 
to  winter  would  change  the  length  of  a  rock  half  a  mile  in 
length  ?  Which  would  be  affected  more,  layers  of  rock  on  the 
surface  or  layers  of  rock  underneath  these  ? 


Part  II 

Make  a  freezing  mixture  consisting  of  two  parts  ice  to  one 
part  salt.  Allow  it  to  stand  until  the  brine  is  two  or  three 
inches  deep.  Fill  a  small  test  tube  half  full  of  water  and  put  it 
in  the  freezing  mixture,  being  careful  not  to  allow  any  of  the 
salt  or  brine  to  enter  the  test  tube.  Be  sure  that  the  water  line 
in  the  test  tube  is  below  the  level  of  the  brine.  Let  it  stand 
until  it  is  frozen.  Examine  the  test  tube.  What  has  occurred? 
Account  for  this. 


THE  ASSOETING  POWER  OF  WATER  105 

Water  enters  the  minute  crevices  of  rocks,  fills  small  cracks, 
and  freezes.  What  effect  must  this  have  upon  the  rock  ?  What 
portion  of  the  rock  will  it  affect  the  most?  Will  a  stone  monu- 
ment endure  longer  in  a  moist  or  a  dry  climate  ? 

EXERCISE  XXXn 
THE  ASSORTING  POWER  OF  WATER 

Mix  clay,  sand,  and  gravel.  Put  them  in  a  bottle  of  water 
and  shake  well.  Let  the  mixture  stand  for  a  time  and  watch 
the  settling  process.  Which  of  the  solids  settles  first?  Let  the 
bottle  stand  over  night  and  observe  again.  Which  settles  last? 
Make  a  drawing  of  the  bottle,  sediment,  and  water. 

Arrange  an  artificial  stream  with  a  steep  slope  in  its  upper 
course  and  a  gentle  slope  in  its  lower  course.  Into  the  upper 
course  put  slowly  some  of  the  mixture  of  clay,  sand,  and  gravel. 
Which  one  is  deposited  first  ?  Why  ?  Which  is  carried  farthest  ? 
Why? 

Look  for  a  stream  in  which  the  above  conditions  exist,  that 
is,  one  that  changes  from  a  steep  slope  in  its  upper  course  to  a 
gentle  slope  in  its  lower  course.  Do  you  find  a  deposit  of  sedi- 
ment? Do  you  find  materials  deposited  in  order,  as  you  did 
with  the  artificial  stream?  If  so,  make  a  drawing  or  a  map, 
indicating  by  dots,  circles,  or  angular  figures  the  size,  shape, 
and  distribution  of  the  material. 

When  a  stream  flows  into  the  ocean,  which  part  of  its  load  do 
you  think  it  deposits  first?  Which  part  is  deposited  farthest 
from  shore  ? 

EXERCISE  XXXIII 

EXAMINATION  OF  ROCK  WASTE 

Part  I 

Examine  a  rocky  cliff  in  a  place  where  there  has  been  no 
disturbing  influence  which  would  remove  material  from  the 
base  of  the  cliff.    Of  what  is  this  collection  of  material  made 


106  PHYSICAL  GEOGRAPHY  MANUAL 

up?  Examine  the  sand  and  gravel  found  here.  What  is  the 
color  ?  Is  it  clean  or  dirty  ?  Are  the  edges  sharp  or  rounded  ? 
Do  you  find  any  vegetable  matter  mixed  with  the  sand  and 
gravel?  Do  you  find  any  very  fine  particles  which,  if  carried 
away  by  water,  might  form  silt  ? 

Part  II 

Visit  the  bed  of  a  stream  which  has  recently  contained  a 
somewhat  brisk  current.  Locate  a  place  which  has  sand  and 
pebbles.  Give  the  color  of  the  sand  and  pebbles.  Are  they 
clean  or  dirty  ?  Are  the  edges  sharp  or  rounded  ?  Do  you  find 
any  vegetable  matter  mixed  with  the  sand  and  pebbles?  Do 
you  find  any  very  fine  particles  which  you  might  call  silt? 
Compare  each  answer  with  the  corresponding  answer  in  Part  I, 
and  account  for  any  difference. 

If  a  stream  carries  much  sand  and  gravel,  what  effect  will  it 
have  upon  the  rocks  over  which  it  flows  ?  How  will  this  affect 
the  sand  and  gravel  ? 

EXERCISE  XXXIV 
A   WATERFALL 

Locate  by  map  or  description  the  waterfall  which  you  examine. 
Locate  the  gorge  with  reference  to  the  fall.  What  agent  has 
been  most  effective  in  making  the  gorge  ?  What  has  become  of 
the  material  which  has  been  removed  ?  Which  resists  erosion 
better,  the  rock  over  which  the  water  is  falling  or  the  material 
beneath  this  rock?  Compare  the  fall  rock  with  the  material 
underneath.  What  difference  in  structure  would  produce  rapids 
instead  of  a  waterfall  ?  What  effect  is  the  flowing  water  having 
on  the  fall  rock  ?  What  aids  the  water  in  this  work  ?  Has  the 
fall  always  been  at  this  point?  What  effect  will  a  continued 
flow  of  water  have  upon  the  location  of  the  fall?  Define  migra- 
tion as  applied  to  a  waterfall. 

Use  cross-section  paper  and  draw  the  following  sections,  using 
suitable  horizontal  and  vertical  scales :  (1)  cross  section  of  the 


RIVER  FLOOD  PLAINS  107 

gorge  and  stream  below  the  fall;  (2)  cross  section  of  the  gorge 
and  stream  above  the  fall ;  (3)  longitudinal  section  of  the  gorge 
and  stream  through  the  fall.  In  drawing  the  longitudinal  section 
do  not  represent  the  sides  of  the  gorge.  In  all  sections  indicate  the 
nature  of  the  soil  or  rock  by  signs  or  shading  chosen  for  the  pur- 
pose. Give  proper  titles  to  your  sections  and  indicate  the  scale. 
If  no  waterfall  is  accessible,  refer  to  the  Canyon  (Wyo.)  sheet 
(topographic  map  of  the  United  States  Geological  Survey)  and 
make  the  sections  called  for,  using  suitable  horizontal  and  vertical 
scales.  Answer  as  many  of  the  questions  as  you  can  by  referring 
to  the  map,  or  from  other  sources  of  information. 


EXERCISE  XXXV 

RIVER  FLOOD  PLAINS 

Part  I 

Visit  a  river  bottom.  Describe  color,  texture,  and  depth  of 
the  soil.  Is  bottom  land  considered  good  farm  land?  Why? 
How  does  it  differ  from  the  adjacent  higher  land?  Do  you 
find  any  pebbles,  bowlders,  or  other  rounded  rocks  in  the  soil? 
If  so,  how  do  you  suppose  they  came  to  be  there  ?  How  high 
does  the  water  come  in  the  times  of  the  highest  floods?  Does 
it  make  any  deposit  at  this  time?  If  so,  what  is  the  nature 
of  the  deposit?  How  wide  is  this  bottom  or  flood  plain  from 
bank  to  bank  ? 

Part  II 

Refer  to  the  Donaldsonville  (La.)  sheet,  topographic  map  of 
the  United  States  Geological  Survey.  Give  approximately  the 
area  in  square  miles  of  the  region  represented.  (See  the  scale 
at  the  bottom  of  the  sheet.) 

What  river  is  here  shown?  What  portion  of  the  river? 
Locate  Donaldsonville  with  reference  to  New  Orleans.  What 
portion  of  this  quadrangle  is  a  swamp?  That  part  between 
the  river  and  the  swamp  is  the  natural  levee.    How  wide  is 


108  PHYSICAL   GEOGKAPHY  MANUAL 

the  natural  levee,  measuring  across  the  river?  How  high 
is  it  above  the  swamp?  What  was  the  active  agent  in  the 
formation  of  the  natural  levee?  Explain  why  it  is  higher 
than  the  swamp.  What  direction  do  the  small  streams  take? 
Why  do  they  not  flow  toward  the  river?  Into  what  do 
they  finally  flow  ?  Are  the  swamps  of  any  value  to  men  ?  Of 
what  disadvantage  are  they?  Could  they  not  be  drained  and 
utilized  ? 

What  is  the  contour  interval  of  the  map?  (See  the  bottom 
of  the  sheet.)  How  can  you  distinguish  a  steep  slope  from  a 
gentle  one  by  aid  of  the  contour  lines  ?  (See  Exercise  XXIX, 
Part  II.)  Compare  the  steepness  of  the  slope  of  the  levee  at 
Nita  crevasse  with  the  steepness  just  above  or  just  below  the 
crevasse.  An  artificial  levee  has  been  built  at  Nita  crevasse. 
How  long  is  the  artificial  part?  (You  can  tell  by  its  being  so 
much  narrower  than  the  natural  levee.)  How  high  above  the 
wagon  road  is  the  artificial  part?  What  have  you  read  about 
artificial  levees  elsewhere  on  the  Mississippi  river?  What  kind 
of  formation  do  you  find  in  the  margin  of  the  swamp  north- 
east of  Nita  crevasse  ?  Account  for  this.  Read  about  the  Nita 
crevasse  in  Davis'  Elementary  Physical  Geography,  pp.  264-265. 
Record  what  you  read,  putting  it  in  your  own  words,  but  telling 
where  you  obtained  the  information. 

Where  are  most  of  the  houses  in  this  quadrangle  situated? 
Compare  the  direction  of  the  railroads  and  the  general  course 
of  the  stream.  What  is  the  principal  industry  of  this  region? 
(See  p.  4  of  Folio  1,  and  give  the  source  of  your  information.) 

Part  III 

Fig.  14' shows  a  part  of  the  narrow  flood  plain  of  the  Merced 
river  in  the  Yosemite  valley.  Of  what  kind  of  material  does 
the  soil  seem  to  be  composed  ?  What  evidences  of  fertility  do 
you  observe  ?  How  many  feet  must  the  river  rise  in  order  to 
overflow  the  flood  plain?  In  what  time  of  year  is  this  most 
likely  to  occur? 


-  a 

-  <s 
r  to 

t  < 


5    a 


13 


109 


110  PHYSICAL  GEOGRAPHY  MANUAL 

EXERCISE  XXXVI 

MEANDERS 

Part  I 

In  the  river  flood  plains  which  you  visited  in  Exercise  XXXV, 
nearer  which  bluff  (right  or  left)  does  the  river  flow?  How 
near  does  it  approach  this  bluff  ?  Does  the  river  cross  the  flood 
plain?  Does  it  make  large  S-shaped  curves?  What  name  is 
given  to  such  curves  ?  Observe  the  banks  of  the  river  near  the 
sharpest  point  of  a  curve.  Is  the  bank  precipitous  on  the  inside 
or  the  outside  of  the  curve  ?  Describe  the  lay  of  the  land  which 
forms  the  bank  on  the  inside  of  the  curve.  Of  what  kind  of 
material  is  it  composed  ?  Near  the  point  of  the  curve  does  the 
main  current  of  the  river  flow  nearer  the  inside  bank  or  the  out- 
side bank?  Which  bank  will  it  erode  more  rapidly?  Does  it 
make  a  deposit  along  either  bank  ?  If  so,  on  which  side  of  the 
curve  ?  Why  does  it  deposit  material  on  this  side  ?  Will  con- 
tinued erosion  by  the  river  tend  to  make  the  curve  more  or  less 
pronounced  ? 

Note.  A  stream  may  be  so  small  and  narrow  that  you  can  step  across 
it,  and  still  it  may  have  such  curves  as  are  discussed  in  this  exercise. 

Part  II 

In  what  part  of  Missouri  is  Marshall?  How  far  is  it  from 
St.  Louis  ?  In  which  direction  does  the  river  flow  in  the  region 
represented  on  the  Marshall  sheet  ?  (See  topographic  map  of  the 
United  States  Geological  Survey.)  Measure  the  entire  length 
of  the  river  represented  here,  following  the  main  channel.  Also 
measure  the  distance  straight  across  and  compare  the  two  meas- 
urements. How  wide  is  the  river  bottom  or  flood  plain  from 
bluff  to  bluff,  just  south  of  Carrollton?  at  Miami?  at  Bruns- 
wick? at  New  Frankfort?  About  what  is  the  average  width? 
How  many  times  does  the  river  bend  toward  the  north  bluff? 
the  south  bluff?    What  name  is  given  to  these  big  S-shaped 


MEANDERS  111 

curves?  Why  does  the  river  follow  such  a  crooked  course 
instead  of  flowing  in  a  more  direct  one?  Why  is  it  called  a 
graded  river?    What  is  meant  by  base  level  of  erosion  F 

On  which  side  of  Prunty  island  does  the  principal  part  of  the 
stream  flow  ?  Observe  the  sand  in  this  part.  Is  it  on  the  inside 
or  outside  of  the  curve  ?  On  which  side  of  the  curve  (inside  or 
outside)  is  the  main  channel  ?  At  the  following  bends  in  the  river 
observe  on  which  side  the  deposit  of  sand  is  found,  and  on  which 
side  the  main  channel  is  found :  (1)  between  Prunty  island  and 
Miller  island ;  (2)  north  of  Miami ;  (3)  northeast  of  Dewitt. 
Do  you  find  it  the  same  in  each  ?  Did  you  find  it  the  same  in 
Part  I  ?  Why  is  the  sand  deposited  on  the  side  on  which  you 
find  it  rather  than  on  the  other  ?  On  which  side  does  the  river 
flow  more  swiftly?  On  which  side  will  it  cut  the  bank  more 
rapidly  ?  What  effect  will  this  have  on  the  size  of  the  S-shaped 
curves?  Observe  the  sharp  curve  near  the  east  side  of  the 
quadrangle.  What  will  be  the  fate  of  the  peninsula  projecting 
from  the  south  side  ?  What  will  be  the  fate  of  that  portion  of 
the  stream  north  of  the  peninsula  ?  How  were  Davis  lake,  Back- 
bone lake,  and  Grand  Pass  lake  formed  ? 

Do  you  think  erosion  is  greater  on  the  bottom  or  the  sides  of 
the  channel  ?  Is  the  rate  of  erosion  of  the  stream  greater  or  less 
than  the  rate  of  deposition?  What  kind  of  material  do  you 
think  is  deposited  here?  Would  such  deposit  make  fertile  soil? 
Do  you  think  of  any  disadvantages  that  the  owner  of  a  farm  in 
the  bottom  might  suffer?  Judging  by  the  number  of  towns  and 
villages,  do  you  think  this  region  is  thickly  settled? 

Part  III 

Examine  Fig.  14  and  describe  everything  you  see  which  is 
similar  to  the  river  forms  discussed  in  Parts  I  and  II  of  this 
exercise.  How  will  the  trees  affect  the  rate  of  cutting  of  the 
bank  by  the  stream  ? 


112  PHYSICAL   GEOGRAPHY  MANUAL 

EXERCISE  XXXVII 
ALLUVIAL  CONES 

In  what  part  of  California  is  the  region  represented  by  the 
Cucamonga  sheet  ?  (See  topographic  map  of  the  United  States 
Geological  Survey.)  Pomona  is  the  largest  town  shown  on  the 
sheet.  How  far  is  it  from  Los  Angeles  ?  What  portion  of  this 
region  is  mountainous?  In  what  direction  is  the  general  slope 
in  the  southern  part  of  this  quadrangle  ? 

San  Antonio  canyon  is  a  deep  and  narrow  gorge  cut  in  the 
southern  slope  of  the  mountain  range.  From  an  elevation  of 
2600  feet  down  to  the  mouth  of  the  canyon  (2250  feet)  the 
creek  has  deposited  great  quantities  of  bowlders,  pebbles,  and 
other  materials.  This  is  called  a  wash.  How  is  it  represented 
on  the  map  ?  Account  for  this  deposit.  How  far  south  of  the 
mouth  of  the  canyon  can  you  trace  the  wash?  Describe  the 
general  shape  of  the  contour  lines  for  several  miles  south  of 
the  mouth  of  the  canyon.  Does  this  indicate  that  the  land 
surface  is  convex  or  concave?  The  San  Bernardino  base  line 
crosses  the  1600-feet  contour  line  north  of  North  Ontario  and 
again  north  of  Claremont.  What  is  the  elevation  of  the  base 
line  midway  between  these  two  points  of  crossing  ?  Does  this 
prove  or  disprove  your  statement  about  the  convex  or  concave 
surface  which  is  represented  here  ?  Are  river  valleys  usually 
convex  or  concave  ?  Why  is  this  one  as  it  is  ?  What  name  is 
given  to  such  a  land  formation  ?  Of  what  kind  of  material  is 
it  composed?  What  difference  in  kind  of  deposit  would  you 
expect  to  find  in  the  wash  within  the  canyon  and  on  the  slopes 
at  Pomona  and  Ontario  ?  (See  Exercise  XXXHI.)  Is  the  soil 
at  the  latter  places  fertile  ?  How  do  you  know  ?  Describe  the 
wash  from  the  mouth  of  the  canyon  to  the  town  of  Claremont 
and  the  A.  T.  &  S.  F.  railroad.  What  name  is  given  to  the 
smaller,  branching  parts?  Account  for  their  formation.  In 
what  respects  is  an  alluvial  cone  similar  to  a  delta  ?  In  what 
respects  is  it  different? 


ALLUVIAL  CONES 


113 


Near  the  point  where  Stoddard  canyon  enters  San  Antonio 
canyon  the  stream  becomes  intermittent,  and  near  the  mouth  of 
the  canyon  it  disappears  altogether.  What  becomes  of  the  water? 
Between  Pomona  and  Chino  a  little  stream  rises.  Where  does 
the  water  probably  come  from  ?  Throughout  this  alluvial  cone 
much  water  is  pumped  from  deep  wells  and  is  used  for  irriga- 
tion.   Where  does  this  water  come  from? 

Determine  the  elevation  of  the  bed  of  the  stream  where  Bear 
canyon  enters  San  Antonio  canyon.     What  is  the  fall  in  feet 


Fig.  15.  a  Debris  Fan  at  Glenwood  Springs,  Colorado,  formed  at  the 
Mouth  of  a  Side  Gorge 

Grand  river  in  the  foreground 


from  this  point  to  the  mouth  of  San  Antonio  canyon  ?  What  is 
the  average  fall  in  feet  per  mile  ?  What  is  the  average  fall  in 
feet  per  mile  from  the  mouth  of  San  Antonio  canyon  due  south 
to  the  edge  of  the  map?  Which  is  the  steeper  slope,  above 
or  below  the  mouth  of  the  canyon? 

Name  the  canyons    represented  on  the    Cucamonga   sheet, 
whose  streams  are  building  up  cones.    What  does  the  author 


114  PHYSICAL  GEOGRAPHY  MANUAL 

of  Folio  2  say  about  the  extent  of  alluvial  cones  in  south- 
ern California  and  elsewhere?  Give  the  conditions  of  slopes 
and  climate  which  are  favorable  to  the  formation  of  alluvial 
cones. 

Fig.  15  shows  a  debris  fan  or  alluvial  cone  formed  by  a 
tributary  of  the  Grand  river,  at  Glenwood  Springs,  Colorado. 
About  what  angle  does  the  slope  of  the  fan  form  with  the 
horizontal?  What,  if  anything,  is  there  here  which  would 
lead  you  to  believe  that  the  slope  of  the  side  canyon  is  steeper 
than  that  of  the  fan  ? 

EXERCISE  XXXVIII 
A  REGION  IN  YOUTH 

Locate  Yellowstone  park  on  a  large  map  of  the  United  States. 
Give  the  part  of  the  state  in  which  it  is  located.  What  stream 
drains  Yellowstone  lake  ?  What  is  the  general  direction  of  that 
portion  of  the  stream  which  is  shown  on  the  Canyon  sheet? 
(See  topographic  map  of  the  United  States  Geological  Survey.) 
Into  what  does  this  river  flow?  What  is  the  elevation  above 
sea  level  of  the  surface  of  Yellowstone  lake  ?  (See  small  brown 
figures  near  the  printed  name.)  What  is  the  elevation  of  the 
river  at  the  lowest  point  shown  on  this  map?  (Count  down 
from  the  contour  line  of  6000  feet.)  Measure  in  miles  the  length 
of  this  portion  of  the  river  and  calculate  the  fall  per  mile. 

How  many  miles  from  Yellowstone  lake  are  the  falls  ?  Give 
height  of  each  of  the  falls.  The  Grand  Canyon  of  the  Yellow- 
stone begins  at  the  falls.  How  deep  is  this  canyon  opposite  the 
letter  a  in  the  word  "  canyon  "  ?  How  wide  is  it  at  this  point  ? 
Does  this  river  have  a  flood  plain?  Which  is  probably  greater, 
the  rate  of  erosion  or  of  deposition  ?  Is  the  stream  capable  of 
carrying  a  large  load?  Give  reasons  for  your  answer.  What 
effect  will  continued  erosion  probably  have  upon  the  width 
and  depth  of  the  canyon? 

Count  the  number  of  tributaries  on  one  side  of  the  Yellow- 
stone river  from  Yellowstone  lake  to  the  northwest  corner  of 


A  REGION  IN   YOUTH 


115 


the  quadrangle,  omitting  those  not  named.  What  is  the  average 
distance  in  miles  between  the  mouths  of  these  tributaries?  If 
Yellowstone  river  deepens  its  channel  at  the  outlet  of  the  lake,, 
how  will  the  water  level  of  the  lake  be  affected,  all  other  con- 
ditions remaining  unchanged?  If  the  falls  should  migrate  as 
far  upstream  as  the  lake  and  disappear  in  the  lake,  how  would 
the  water  level  of  the  lake  be   affected,  all  other  conditions 


Fk;.  1(3.   A  Terrace,  150  Feet  in  Height,  cut  by  the  Santa  Aua  liiver, 
Southern  California 

Some  of  the  best  orange  groves  in  the  world  are  located  on  this  terrace 

remaining  unchanged?  Lakes  are  an  evidence  of  uncompleted 
work  or  imperfect  drainage.  What  other  evidence  of  imperfect 
drainage  do  you  find  on  this  quadrangle  ?  (Look  along  Pelican 
creek,  which  flows  into  Yellowstone  lake,  and  along  Slough 
creek,  in  the  extreme  northern  part  of  the  quadrangle.)  If 
draining  this  region  were  the  task  of  the  Yellowstone  river, 
would  you  say  it  has  much  or  little  yet  to  do  ? 


a 

a 
O 


116 


A  REGION  IN  MATURITY  117 

The  region  represented  on  the  large  map  ^  is  a  great  plateau. 
It  is  being  cut  by  canyons  into  smaller  plateaus.  Determine 
and  record  the  average  elevation  of  each  of  the  following  pla- 
teaus (see  large  map) :  (1)  Buffalo  plateau  ;  (2)  Mirror  plateau  ; 
(3)  Two  Ocean  plateau ;  (4)  Pitchstone  plateau ;  (5)  Madison 
plateau  ;  (6)  Central  plateau.  Which  is  highest  ?  Do  you  detect 
any  slope  away  from  this  plateau?  If  so,  in  what  direction? 
Observe  the  picture  of  the  canyon  of  the  Yellowstone.  (See 
Fig.  17.)  The  background  represents  one  of  these  plateaus. 
Describe  the  sky  line.  If  one  were  standing  on  this  plateau, 
the  higher  portions  would  appear  as  mere  undulations  of  the 
surface.  Distant  canyons  would  not  be  visible.  Why?  What 
effects  will  continued  erosion  probably  have  upon  the  general 
appearance  of  this  plateau? 

Why  is  it  appropriate  to  say  that  this  stream  and  this  region 
are  in  their  youth  ? 

EXERCISE  XXXIX 

A  REGION  IN  MATURITY 

Part  I 

Locate  Charleston  (W.Va.),  giving  the  river  on  which  it  is 
located  and  the  distance  from  the  point  where  it  flows  into  the 
Ohio  river.  Count  the  tributaries  on  one  side  of  the  Kanawha 
below  Charleston  (see  the  Charleston  sheet,  topographic  map  of 
the  United  States  Geological  Survey),  omitting  those  without 
printed  names.  Are  any  of  them  intermittent  ?  What  would  you 
infer  about  the  rainfall  of  this  region?  Measure  the  distance 
along  the  river  from  Charleston  to  the  last  tributary  which  is 
shown.  Give  the  average  distance  in  miles  between  tributaries. 
Compare  this  with  that  shown  on  the  Yellowstone  canyon  sheet. 

What  is  the  contour  interval?  Are  the  contour  lines  near 
together  or  far  apart?    If  the  contour  interval  were  20  feet,  as 

1  Assembled  topographic  sheets  of  the  United  States  Geological  Survey,  as 
shown  on  page  170. 


118  PHYSICAL  GEOGRAPHY  MANUAL 

it  is  on  some  sheets,  would  the  lines  here  be  more  or  less  numer- 
ous ?  Would  they  be  nearer  each  other  or  farther  apart  ?  Are 
the  sides  of  the  valleys  steep  or  gentle  in  slope  ?  Are  the 
divides  pronounced  or  indistinct?  Is  the  drainage  perfect  or 
imperfect?  Characterize  this  region  as  levels  rolling,  or  broken. 
What  kind  of  soil  has  this  region?  Give  reasons  for  your 
answer.  In  what  direction  do  the  wagon  roads  run?  Why? 
How  far  across  country  could  one  go  without  crossing  a  wagon 
road?    Do  you  think  this  region  is  thickly  or  sparsely  settled? 

Part  II 

Hickory  Knob  is  about  two  miles  from  the  north  boundary 
of  the  quadrangle  and  five  miles  from  the  west  boundary.  Its 
elevation  is  printed  in  brown  just  above  the  name.  How  high 
above  sea  level  is  it?  Find  the  elevation  of  the  following 
knobs,  which  are  nearly  in  a  straight  line  extending  south  from 
Hickory  Knob,  and  make  a  list  of  them  with  their  elevations : 
(1)  Hickory  Knob;  (2)  Big  Rocks,  about  nine  miles  south  of 
Hickory  Knob;  (3)  Sugar  Camp  Knob,  nine  or  ten  miles  south 
of  Big  Rocks ;  (4)  Blue  Knob,  five  miles  southwest  of  Sugar 
Camp  Knob ;  (5)  an  unnamed  knob  about  three  miles  from  the 
southwest  corner  of  the  quadrangle.  Suppose  this  region  was 
once  a  plateau  as  high  as  the  tops  of  these  knobs,  and  suppose 
the  original  plateau  restored  as  it  was  at  that  time.  How  high 
was  the  plateau  at  the  south?  at  the  north?  Which  way  did 
it  slope?  What  was  the  fall  per  mile?  Does  the  Kanawha 
river  now  have  as  great  a  slope  as  the  plateau  that  you  have 
described  ? 

The  highest  point  near  the  southeast  corner  of  the  quadrangle 
is  in  Fork  Ridge,  three  miles  from  the  east  boundary  and  seven 
or  eight  miles  from  the  south  boundary.  How  high  is  it  ?  Com- 
pare this  with  the  elevation  of  Blue  Knob,  which  is  almost  due 
west  of  Fork  Ridge.  The  highest  point  near  the  northeast  corner 
of  the  quadrangle  is  about  1300  feet  above  sea  level.  Compare 
this  with  the  elevation  of  Hickory  Knob  at  the  northwest  corner. 
Do  you  detect  a  slope  toward  either  east  or  west  ?    What  was 


A  EEGION  m  OLD  AGE  119 

the  true  direction  of  the  slope  of  the  original  plateau  ?  Compare 
this  with  the  general  direction  of  the  Kanawha  river.  Henry 
Gannett  says  that  this  region  was  once  just  such  a  plateau  as 
we  have  described.  How  has  it  been  changed  from  a  plateau 
to  the  skeleton  of  a  plateau  that  you  now  see  on  the  map  ? 

EXERCISE  XL 
A   REGION  IN  OLD  AGE 

In  what  part  of  Kansas  is  Caldwell?  What  is  the  contour 
interval  of  the  Caldwell  sheet?  (See  topographic  map  of  the 
United  States  Geological  Survey.)  If  the  contour  interval  were 
1 00  feet,  as  it  is  on  the  Charleston  sheet,  how  would  the  number 
of  lines  here  compare  with  what  it  is?  Are  the  slopes  gentle 
or  steep?  Are  the  valleys  wide  or  narrow?  Are  the  divides 
pronounced  or  indistinct  ?  How  is  it  possible  to  build  railroads 
in  so  many  different  directions  ?  What  directions  do  the  wagon 
roads  take  ?  How  far  apart  are  they  ?  In  which  does  the  land 
lie  better  for  farming,  this  or  the  Charleston  quadrangle  ? 

The  author  of  this  folio  tells  us  that  the  Caldwell  region  has 
gone  through  the  stages  of  youth  and  maturity.  What  proof  of 
this  does  he  find  in  the  position  of  the  rocks  ?  What  is  a  pene- 
plain? (See  the  text-books.)  What  is  meant  by  base  level  of 
erosion  ?  Account  for  the  big  bends  in  the  Chikaskia  river  below 
Argonia.    Account  for  the  lake  or  pond  just  west  of  Caldwell. 

In  this  region  the  average  annual  rainfall  is  about  20  inches, 
an  amount  very  much  less  than  that  of  the  Charleston  quad- 
rangle. In  which  region  would  erosion  be  greater  if  it  depended 
upon  this  alone  ?  In  the  Caldwell  quadrangle  the  surface  of  the 
land  is  almost  naked,  whereas  in  the  Charleston  quadrangle  it  is 
covered  with  dense  forests.  In  which  region  would  erosion  be 
greater  if  it  depended  upon  this  alone  ?  In  the  Caldwell  region 
the  underlying  and  outcropping  rocks  are  much  softer  than  those 
of  the  Charleston  region.  In  which  would  erosion  be  greater  if 
it  depended  upon  this  alone  ?  In  which  would  it  be  greater  if 
it  depended  alone  upon  the  steepness  of  the  slopes  ?    Which  of 


120  PHYSICAL  GEOGEAPHY  MANUAL 

these  conditions  of  erosion  can  man  modify  ?    What  effect  does 
erosion  have  upon  the  fertility  of  the  surface  that  is  being  eroded  ? 

EXERCISE  XLI 
THE  LIFE  HISTORY  OF  A  RIVER 

Make  an  outline  of  the  life  history  of  an  ideal  river.  Make  it 
in  three  parts  as  follows  :  (1)  a  young  river ;  (2)  a  mature  river; 
(3)  an  old  river. 

In  each  part  consider :  (1)  steepness  of  slope ;  (2)  swiftness 
of  current;  (3)  character  of  load;  (4)  cutting  power;  (5)  num- 
ber of  tributaries ;  (6)  shape  of  cross  section  of  valley ;  (7)  per- 
fect or  imperfect  drainage ;  (8)  fall  per  mile  from  source  to 
mouth ;  (9)  longitudinal  profile  ;  (10)  presence  of  lakes,  canyons, 
waterfalls,  rapids,  flood  plains,  meanders,  delta. 

EXERCISE  XLII 
THE  DRAINAGE  AREAS  OF   THE   UNITED   STATES 

Use  an  outline  map  of  the  United  States  and  draw  the  divides 
around  the  following  drainage  basins :  St.  Lawrence,  Mississippi, 
Columbia,  Colorado,  Great  Basin.  Draw  also  the  divides  bound- 
ing the  following  slopes :  Atlantic,  Gulf  of  Mexico  east  of  the 
Mississippi  river,  Gulf  of  Mexico  west  of  the  Mississippi  river. 
Pacific  slope. 

Color  these  regions  so  that  no  two  adjacent  shall  have  the 
same  color.  Rub  in  the  colors  well.  Write  an  explanation  of 
colors,  or  legend,  in  an  appropriate  place  on  the  map. 

EXERCISE  XLIII 

THE  MIGRATION  OF  DIVIDES 

What  large  river  is  shown  on  the  Doylestown  (Pa.-N.  J.) 
sheet?  (See  topographic  map  of  the  United  States  Geological 
Survey.)  About  how  far  from  Philadelphia  is  this  portion  of 
the  river  ?    In  what  direction  from  Philadelphia  ? 


THE  MIGRATION  OF   DIVIDES  121 

Tinicum  creek  flows  into  'Delaware  river  near  the  northern 
boundary  of  the  quadrangle.  It  is  a  crooked  stream,  flowing 
first  toward  the  southeast  and  then  toward  the  northeast.  What 
is  the  elevation  of  the  first  point  of  its  headwaters,  which  is 
shown  on  the  north  side  of  the  map  ?  What  is  the  average  fall 
in  feet  per  mile  ? 

Tohickon  creek  is  a  very  much  longer  stream,  which  flows 
into  the  river  at  Point  Pleasant.  What  is  the  elevation  of  the 
first  point  of  this  stream,  which  is  shown  on  the  west  side  of 
the  map  ?  What  is  the  rate  of  fall  ?  Which  is  the  more  vigor- 
ous stream,  Tohickon  or  Tinicum  creek  ? 

Near  the  large  bend  in  Tinicum  creek  there  is  a  small  trib- 
utary which  enters  from  the  southwest.  This  tributary  has  its 
headwaters  near  a  fork  in  the  road,  about  a  mile  and  a  half 
southeast  of  Ottsville.  At  this  point  the  road  is  on  the  divide 
between  Tinicum  and  Tohickon  creeks.  How  high  above  sea 
level  is  the  divide  at  this  point?  What  is  the  elevation  of 
Tohickon  creek  near  this  point?  How  many  feet  would  have 
to  be  removed  from  the  divide  to  make  it  the  same  level  as  the 
water  in  Tohickon  creek  ? 

Which  stream  will  erode  its  basin  more  rapidly,  all  conditions 
except  the  slope  being  equal?  What  effect  will  this  have  upon 
the  size  of  its  basin?  upon  the  size  of  the  other  basin?  In 
which  direction  will  the  divide  probably  move  at  the  point 
southeast  of  Ottsville?  If  the  divide  should  move  a  mile  in 
the  direction  which  you  indicate,  what  change  would  occur  in 
the  course  of  Tohickon  creek?  This  action  of  the  stream  is 
called  beheading.  Which  stream  is  in  danger  of  being  beheaded  ? 
How  large  an  area  in  square  miles  is  liable  to  be  cut  off  in  this 
way  ?    Consider  only  the  region  shown  on  this  map. 

If  these  streams  were  furnishing  power  for  manufacturing, 
how  might  the  result  of  migration  of  divides  affect  the 
industry  ? 


122  PHYSICAL  GEOGRAPHY  MANUAL 

EXERCISE  XLIV 
SPECIFIC   GRAVITY 

With  a  string  tie  a  stone  to  the  hook  on  one  pan  of  the 
specific-gravity  balance.  Weigh  the  stone.  Place  the  balance 
and  the  stone  in  such  a  position  that  the  stone  will  be  com- 
pletely immersed  in  a  vessel  of  water,  but  do  not  allow  the 
scale  pan  to  touch  the  water.  With  the  stone  in  the  water, 
weigh  it  again.  Does  it  weigh  more  or  less  than  it  did  before  ? 
How  much  ?  Why  does  it  weigh  less  under  one  condition  than 
under  the  other? 

If  the  stone  should  be  removed,  the  space  that  it  now  occupies 
would  be  filled  with  water.  At  present  it  displaces  the  water. 
Compare  the  volume  which  it  displaces  with  the  volume  of  the 
stone.  The  volume  of  the  water  displaced  weighs  just  as  much 
as  the  difference  between  the  two  weights  of  the  stone  obtained 
above.  You  may  be  called  upon  to  prove  this  some  day ;  now 
we  must  accept  it  without  proof.  Give  a  rule  for  finding  the 
weight  of  the  water  displaced  by  a  stone  immersed  in  it.  Give 
a  rule  for  finding  the  weight  of  water  equal  in  volume  to  the 
volume  of  a  stone. 

Compare  the  weight  of  the  stone  with  the  weight  of  an  equal 
volume  of  water.  The  ratio  of  the  former  to  the  latter  is  called 
the  specific  gravity.  Define  specific  gravity.  Give  a  rule  for  find- 
ing the  specific  gravity  of  a  stone.  The  last  rule  is  the  important 
one.    Remember  it. 

What  is  the  specific  gravity  of  a  stone  which  weighs  just  as 
much  as  an  equal  volume  of  water  ?  (If  in  doubt,  assume  that 
each  weighs  50  grams,  and  calculate  it  according  to  your  rule.) 
What  is  the  specific  gravity  of  a  stone  which  weighs  less  than 
an  equal  volume  of  water?  (Give  answer  as  equal  to,  greater, 
or  less  than  that  of  the  preceding.) 

In  writing  your  notes  draw  or  describe  the  apparatus. 


VOLCANIC  ROCKS  123 

EXERCISE  XLV 

VOLCANIC   ROCKS 

Paet  I 

Examine  obsidian,  pumice,  and  vesicular  basalt.  Describe 
each  according  to  the  following  schedule : 

Color.  Distinguish  between  dull  black  and  lustrous  black, 
between  light  gray  and  dark  gray. 

Structure.  Is  it  solid,  porous,  fibrous,  crystalline,  or  amor- 
phous ? 

Weight.    Give  specific  gravity. 

Method  of  formation.  Read  text-books,  reference  books,  cyclo- 
pedias, and  dictionary'. 

Remarks.  Anything  that  does  not  readily  come  under  the 
items  given  above,  especially  locality  from  which  your  specimen 
comes. 

Part  II 

Fig.  18  shows  a  mudhole  which  has  dried  up.  Describe  the 
effects  which  have  been  produced.  How  deep  have  you  ever 
known  such  mud  cracks  to  be?  Fig.  19  shows  a  lava  flow  in 
which  the  cracks,  or  joint  planes,  extend  very  deep.  Tell  what 
you  know  of  the  cause  of  their  formation. 

EXERCISE  XLVI 

VOLCANIC  PEAKS,  PLATEAUS,  AND  NECKS 

Refer  to  the  Mt.  Taylor  (N.  M.)  sheet.  (See  topographic  map 
of  the  United  States  Geological  Survey.)  In  what  part  of  New 
Mexico  is  Mt.  Taylor?  What  is  the  highest  point  on  the  moun- 
tain? Two  or  three  miles  east  of  this  highest  point  there  is 
a  stream  formed  by  a  dozen  or  more  small  tributaries.  Trace 
\vith  a  pointer  the  divide  surrounding  the  headwaters  of  these 


124 


PHYSICAL  GEOGRAPHY  MANUAL 


tributaries.  This  divide  is  the  rim  of  an  ancient  crater.  What 
shape  was  the  crater  ?  How  far  is  it  from  the  rim  on  one  side 
to  the  rim  on  the  opposite  side  ?  At  how  many  points  about  the 
crater  does  the  elevation  reach  11,000  feet?  What  is  the  eleva- 
tion of  the  river  bed  at  the  point  where  it  flows  through  the 
rim  of  the  crater?  Near  the  center  of  the  crater  is  a  circular 
hill.  What  is  the  elevation  of  its  summit  above  sea  level  ? 
How  high  is  it  above  the  stream  which  flows  near  its  northern 


Fig.  18.  Mud  Cracks  in  the  Bed  of  an  Intermittent  Stream, 
Southern  California 

side?  This  hill  is  a  volcanic  neck.  How  has  it  been  made? 
(See  picture  and  cross  section  on  the  page  opposite  the  map  in 
Folio  2.)  How  deep  is  the  crater  from  the  rim  to  the  small 
level  area  just  west  of  the  neck? 

What  is  the  average  elevation  above  sea  level  of  the  mesa 
Sierra  Chivato?  of  the  region  10  or  15  miles  northwest  of 
Willow  Spring?    (Count  down  from  the  contour  line  of  7000 


Fig.  19.   Columns  of  Basalt  from  an  Old  Lava  Flow  on  the  North  Fork 
of  the  San  Joaquin  River,  California 


125 


126  PHYSICAL  GEOGRAPHY  MANUAL 

feet.)  How  much  higher  is  the  mesa  than  the  surrounding 
region  ?  Is  the  descent  from  the  mesa  abrupt  or  gentle  ?  With  a 
pointer  trace  the  outline  of  the  mesa.  In  which  direction  does 
it  extend  farthest  from  Mt.  Taylor?  The  author  of  Folio  2 
says,  "  This  is  a  volcanic  mesa,  formed  by  outflows  of  lava 
from  the  mountain  and  probably  from  other  craters  upon 
the  surface  of  the  mesa."  Across  the  Puerco  river  northeast 
of  the  Sierra  Chivato  is  Cabazon  peak,  a  volcanic  neck  more 
than  1000  feet  high.  How  many  volcanic  necks  do  you  see 
between  the  Sierra  Chivato  and  the  Puerco  river?  Volcanic 
necks  "  were  formed  by  the  forcing  of  volcanic  rocks,  in  a 
molten  condition,  up  through  overlying  stratified  beds.  These 
beds,  which  were  much  softer  than  the  lava,  have  since  been 
eroded  away,  leaving  the  neck  of  lava  standing  by  itself." 

EXERCISE  XLVII 
A  CRATER 

Refer  to  the  Crater  lake  (Ore.)  special  sheet.  (See  topographic 
map  of  the  United  States  Geological  Survey.)  Locate  Mt. 
Mazama.  For  what  is  it  remarkable?  What  shape  is  Crater 
lake?  What  is  the  distance  across  it  from  east  to  west?  How 
large  is  the  drainage  basin  which  contributes  its  waters  to  Crater 
lake?  What  is  the  highest  point  on  the  rim  surrounding  the 
lake  ?  At  what  point  would  the  water  first  find  an  outlet  if  the 
surface  of  the  lake  should  rise  above  its  present  level  ?  What  is 
the  elevation  above  sea  level  at  the  surface  of  the  lake  ?  How 
far  is  this  below  the  top  of  the  rim  which  surrounds  the  lake  ? 
Compare  the  steepness  of  the  slope  on  the  inside  of  the  rim 
with  that  on  the  outside.  Could  one  easily  ascend  these  slopes? 
Where  is  the  steepest  part?  See  the  picture  of  this  steepest 
part  on  the  page  opposite  the  map  in  Folio  2. 

Crater  lake  is  most  easily  reached  by  a  wagon  road  from  the 
south,  but  there  is  a  trail  approaching  it  from  the  north.  Com- 
pare the  steepness  of  the  lower  part  of  the  trail  up  as  far  as  the 
first  spring  with  the  slope  of  a  straight  line  from  this  spring  to 


GLACIERS  127 

Llao  rock.  Observe  the  section  at  the  bottom  of  the  sheet,  use 
cross-section  paper,  and  draw  a  similar  section  from  north  to 
south  along  the  meridian  of  122  degrees,  5  minutes.  Let  your 
section  extend  one  mile  beyond  the  lake  both  north  and  south. 
Use  the  same  horizontal  scale  as  on  the  map,  vertical  scale  one 
square  to  1000  feet.  (Blue  figures  show  depths  in  feet  below 
the  surface  of  the  lake.) 

How  does  the  author  of  this  folio  account  for  the  formation  of 
Crater  lake  ?  If  you  have  read  anything  else  of  special  interest 
or  value  concerning  tliis  lake,  record  it  here.  Tell  where  you 
read  it. 

EXERCISE  XLVm 

GLACIERS 

Refer  to  the  Shasta  (Cal.)  special  sheet.  (See  topographic  map 
of  the  United  States  Geological  Survey.)  Locate  Mt.  Shasta. 
Wluit  do  you  find  near  the  summit  of  Mt.  Shasta  which  you 
have  not  seen  on  any  other  mountain  that  we  have  studied? 
How  are  glaciers  indicated  on  the  map?  How  many  do  you 
find  on  Mt.  Shasta?  On  which  side  of  the  mountain  are  the 
largest  ones  found?  In  which  direction  from  the  summit  is 
Hotlum  glacier?  In  which  direction  must  its  ice  be  moving? 
Which  part  must  melt  fastest  ?  Is  Hotlum  widest  in  the  upper, 
middle,  or  lower  part  ?  How  do  you  think  the  thickness  of  the 
ice  in  the  lower  part  compares  with  the  thickness  in  the  mid- 
dle? Give  reasons  for  your  answer.  What  effect  must  the 
moving  ice  have  upon  the  surface  of  the  mountain  over  which 
it  is  moving  ?  What  effect  does  the  friction  on  the  sides  of  the 
valley  have  upon  the  rate  of  movement  of  the  ice  along  the  sides 
of  the  glacier?  Note  the  blue  lines  which  cross  the  glacier. 
Which  way  do  they  bend  in  crossing?  Which  part  of  the 
glacier  probably  moves  fastest  ?  What  effect  will  this  have  upon 
the  texture  of  the  ice  ? 

How  many  little  streams  take  their  rise  just  below  the  lower 
part  of  Hotlum  glacier  ?  Where  do  you  suppose  they  get  their 
supply  of  water  ?    What  does  the  area  of  small  brown  dots  below 


128  PHYSICAL  GEOGRAPHY  MANUAL 

Bolam  glacier  represent  ?  How  does  the  front  of  Bolam  glacier 
differ  in  shape  from  the  front  of  Whitney  glacier?  Do  you 
know  of  any  ancient  glacier  which  was  lobed  ?  When  a  glacier 
spreads  out  at  the  bottom,  as  Hotlum  glacier  does,  will  the 
striae  which  it  makes  be  parallel  or  divergent? 

"  In  the  United  States,  outside  of  Alaska,  there  are  not  many 
mountains  sufficiently  high  to  have  glaciers  upon  them.  In  the 
Rocky  mountains  perennial  fields  of  ice  and  snow  are  almost 
unknown  except  in  northern  Montana.  There  are  several  small 
glaciers  in  the  high  Sierra  of  California,  and  in  the  Cascade 
range  are  found  many  glaciers,  some  of  which  are  of  consider- 
able magnitude.  The  summits  of  Rainier,  Adams,  Hood,  and 
Shasta  are  practically  surrounded  by  glaciers."  Locate  Rainier, 
Adams,  and  Hood. 

EXERCISE  XLIX 
TOPOGRAPHIC   FORMS  DUE   TO   GLACIATION 

Refer  to  the  Sun  Prairie  (Wis.)  and  adjacent  sheets.  (See  topo- 
graphic map  of  the  United  States  Geological  Survey.)  The  Sun 
Prairie  sheet  represents  a  series  of  glacial  hills  which  are  com- 
posed of  unstratified  drift  material,  sand,  and  gravel.  How  high 
are  these  hills  above  the  surrounding  country?  What  is  their 
general  shape  ?  How  wide  are  they  ?  Are  their  tops  sharp  or 
rounded  ?  "  These  hills,  or  drumlins,  Vere  made  not  at  the 
end  of  the  glacier  where  it  melts,  but  along  and  under  the 
bed.  Some  projection  of  the  ground  over  which  it  was  passing 
probably  checked  the  current  of  the  ice  and  made  it  deposit 
part  of  its  load."  What  is  the  general  direction  of  the  trend 
of  the  drumlins?  What  does  this  indicate  as  to  the  direction 
of  the  movement  of  the  glacier  ? 

Observe  the  position  of  the  Sun  Prairie  quadrangle  as  shown 
on  the  large  map.^  See  the  large  map  for  answers  to  the  follow- 
ing questions.    What  is  the  general  trend  of  the  drumlins  along 

1  Assembled  topographic  sheets  of  the  United  States  Geological  Survey,  as 
given  on  page  170. 


TOPOGRAPHIC  FORMS  DUE  TO  GLACIATION     129 


the  east  bank  of  the  Crawfish  river,  west  of  Watertown  ?  along 
Rock  river,  east  and  southeast  of  Watertown  ?  along  Ashippun 
river  north  of  Oconomowoc  ?  These  drumlins  were  formed  under 
the  Green  Bay  lobe  of  the  last  great  glacier  which  swept  down 
over  the  United  States,  at  a  point  not  far  from  the  southern 
boundary  of  the  lobe.  How  do  you  account  for  the  different 
directions  which  they  take? 

Do  you  find  the  trend  from  5  to  15  miles  east  and  southeast 
of  Oconomowoc  to  be  the  same  as  that  north    of   Ashippun 


Fjg.  20.   Section  of  a  Glacial  Moraine  in  the  Rocky  Mountains  on 
the  Line  of  the  Great  Northern  Railroad 

river?  As  the  great  ice  sheet  moved  southward  it  melted  at 
the  southern  border.  When  the  melting  exceeded  the  southward 
movement,  the  front  of  the  glacier  retreated  northward.  When 
the  melting  just  equaled  the  movement  of  the  ice,  the  front  of 
the  glacier  remained  stationary.  One  of  these  pauses  on  its  re- 
treat occurred  in  the  region  southeast  of  Oconomowoc,  also  in  the 
region  shown  on  the  Eagle  sheet  in  Folio  1,  and  in  others  to  the 
south  and  west.  From  what  source  do  you  suppose  the  material 
came  which  makes  up  these  hills  southeast  of  Oconomowoc? 


130 


LAKES  131 

What  name  is  given  to  such  a  formation  ?  Why  are  these  hills 
so  irregular  ?  How  does  this  glacial  formation  differ  from  drum- 
lins  ?  Do  you  find  any  indication  of  a  general  trend  in  the  hills 
represented  on  the  Eagle  sheet?  If  so,  what  relation  does  it 
sustain  to  the  direction  of  the  trend  of  the  nearest  drumlins? 
What  angle  would  you  expect  the  end  of  a  glacier  to  form 
with  the  direction  of  its  movements? 

What  evidence  of  youthful  drainage  do  you  find  ?  If  these 
streams  are  young,  how  do  you  account  for  their  extreme 
crookedness  in  many  cases  ?  They  are  called  consequent  streams. 
Why? 

Fig.  20  shows  a  section  of  a  glacial  moraine.  Describe  the 
general  shape  of  the  slopes  of  this  hill.  Do  you  find  any  evi- 
dences of  stratification  ?  Is  stratification  characteiistic  of  glacial 
deposits  ?  Account  for  this.  Observe  the  bowlders  in  the  fore- 
ground at  the  left.  Describe  their  size  and  shape.  Are  they 
rounded  or  angular  ?  Account  for  this.  What,  besides  bowlders, 
do  you  find  in  this  glacial  deposit? 

EXERCISE  L 
LAKES 
Part  I 

Visit  a  lake,  make  careful  observations,  and,  if  necessary,  seek 
information  from  residents  of  the  vicinity. 

Is  the  water  level  constant  throughout  the  year?  Do  you 
note  any  changes  of  the  average  water  level  from  year  to  year  ? 
If  so,  do  you  find  evidence  that  it  is  higher  than  formerly  ? 
What  evidence?  Do  you  find  evidence  that  it  is  lower  than 
formerly  ?  If  so,  what  evidence  ?  Account  for  any  change 
that  may  have  occurred  in  the  water  level.  Do  you  find  evi- 
dence that  the  lake  is  being  filled  with  sediment?  If  so,  what 
evidence  ?  Is  the  outlet  a  vigorous  stream  ?  Are  its  tributaries 
or  its  outlet  the  greater  menace  to  the  life  of  the  lake?  Of 
what  value  to  man  is  this  lake? 


132  PHYSICAL  GEOGRAPHY  MANUAL 

Part  II 

Refer  to  a  map  of  North  America  and  compare  the  number  of 
lakes  in  Canada  east  of  the  meridian  of  100  degrees  west  longi- 
tude with  the  number  of  lakes  in  the  southern  part  of  the  United 
States.  Refer  to  a  map  of  the  United  States  and  compare  the 
number  of  lakes  east  of  the  Missouri  and  Mississippi  rivers  and 


Fig.  22.    Bear  Lake,  at  an  Elevation  of  6700  Feet,  in  San  Bernardino 
Mountains  of  Southern  California 

The  banks  are  so  steep  that  the  zones  of  vegetation  are  not  marked 

north  of  the  parallel  of  40  degrees  north  latitude  with  the  num- 
ber of  lakes  south  of  this  region.  How  is  the  great  number  in 
one  region  accounted  for? 

Lakes  have  been  called  the  settling  basins  of  the  rivers.  What 
is  there  in  this  name  which  is  appropriate?  Considering  this 
alone,  which  would  you  think  would  have  clearer  waters,  the 
St.  Lawrence  river  or  the  Missouri  ?  How  does  this  agree  with 
what  you  know  of  the  clearness  of  the  water  of  the  two  rivers  ? 

Of  what  value  to  commerce  are  the  Great  Lakes  ? 


LAKES 


133 


Pabt  III 

Examine  Fig.  21.  Locate  the  sedges  with  reference  to  the 
lake.  Compare  the  positions  of  sedges  and  shrubs.  Which 
occupy  drier  ground,  the  shrubs  or  the  pine  trees  ?  The  former 
outlet  of  the  lake  can  be  seen  in  the  background,  leading  toward 
theriofht.    What  kind 


of  growth  now  fills  it  ? 
From  this  picture,  or 
from  other  sources  of 
information,  arrange 
the  following  in  the 
order  of  their  natural 
places  of  growth, 
beginning  with  the 
aquatic  plants:  pine 
trees,  water  lilies,  wil- 
lows, sedges,  grasses. 

Part  IV 

Refer  to  the  Nor- 
folk (Va.)  sheet  (see 
topographic  map  of 
the  United  States 
Geological  Survey), 
and  read  the  descrip-  ^'«-  ^l'  .^^P  «^  the  Ancient  Lake  Bonneville 
^  with  Its  Modern  Representatives,  Great  Salt 

tion  in  Folio  2.   What         ^ake  and  Sevier  Lake 
belts  of  vegetation  are 

found  around  the  margin  of  the  Dismal  swamp  ?  Describe  the 
cypress  trees  by  referring  to  the  picture  in  the  folio.  Accord- 
ing to  the  author  of  this  folio,  which  is  encroaching  on  the 
other,  the  swamp  or  the  region  of  vegetation?  How  is  man 
assisting  in  this  process?  To  what  does  the  soil  of  this 
swamp  owe  its  fertility?  How  is  peat  formed?  How  is 
peat  sometimes  used?  To  what  use  are  men  putting  Lake 
Drummond  ? 


134 


PHYSICAL  GEOGRAPHY  MANUAL 


EXERCISE  LI 
EXTINCT  LAKES 

Refer  to  the  map,  Fig.  23.  What  is  the  length  in  miles  of 
Great  Salt  lake  ?  What  was  the  greatest  length  of  Lake  Bonne- 
ville, according  to  this  map  ?  Give  the  evidences,  so  far  as  you 
know  them,  which  go  to  show  that  Great  Salt  lake  is  a  remnant 
of  Lake  Bonneville.  Was  this  change  in  size  due  to  drainage, 
filling,  or  evaporation?  How  do  you  know?  If  Lake  Bonne- 
ville was  a  fresh-water  lake,  how  do  you  account  for  the  salt- 
ness  of  Great  Salt  lake  ? 

According  to  the  map.  Fig.  24,  how  far  beyond  its  present 
limit  did  the  Gulf  of  California  extend?  How  far  was  the 
mouth  of  the  Col- 


orado river  from 
its  present  mouth? 
The  delta  was 
built  up,  thus  cut- 
ting off  the  head 
of  the  gulf.  The 
river  followed  one 
of  its  distiibutaries 
to  the  lower  por- 
tion of  the  gulf. 
Was  the  newly 
made  lake  salt  or 
fresh  ?  Rainfall  is 
very  light  in  this 
region,  averaging 
from  2  to  5  inches 
annually;  evap- 
oration is  very 
rapid.     Would  time  make  this  lake   more   or  less   salt? 

Except  for  an  occasional  overflow  of  the  Colorado  river, 
this  region  at  present  is  entirely  dry.  What  do  you  suppose 
has  become  of  the  salt?    In  what  part  would  it  probably  be 


Fig.  24.  Map  of  the  Bed  of  the  Ancient  Salton  Sea, 
about  300  Feet  below  Sea  Level,  showing  the  Proba- 
ble Former  Extent  of  the  Gulf  of  California  and  the 
Delta  of  the  Colorado  River 


SOLIDS  IN  SOLUTION 


135 


found  in  the  largest-  quantities  ?  Do  you  think  this  part  would 
make  good  agricultural  land  ?  Why  ?  Some  remarkably  fertile 
soil  is  found  near  the  Mexican  boundary  line  and  in  the  south- 
ern portion  of  this  old  lake  bed.  Explain  why  it  is  fertile. 
Water  for  irriga- 
tion is  brought 
from  the  Colorado 
river.  Does  the 
land  slope  in  the 
right  direction  to 
aid  in  transport- 
ing the  water? 

Read  about 
Death  valley,  tell 
what  of  economic 
importance  is 
found  there,  and 
account  for  its 
presence. 

Locate  the  Dead 
sea.  How  far  be- 
low sea  level  is  its 

present  surface?  (See  Fig.  25.)  How  deep  is  the  water?  If 
this  sea  should  dry  up,  how  far  would  its  bed  be  below  sea 
level  ?    How  far  below  the  level  of  Jerusalem  ? 

Note    any    other   extinct   lakes    that  you   think   worthy  of 
special  mention. 

EXERCISE  LII 
SOLIDS   m   SOLUTION 


Fig.  25.    Contour  Map  of  the  Dead  Sea, 
Palestine,  Western  Asia 


Fill  a  small  beaker  half  full  of  water.  Add  a  very  little 
powdered  alum  and  stir  the  mixture.  Can  you  see  the  alum? 
What  has  become  of  it  ?  It  is  said  to  be  in  solution  ;  water  is 
called  a  solvent  and  alum  is  said  to  be  soluble.    Add  powdered 


136 


PHYSICAL  GEOGEAPHY  MANUAL 


alum  slowly,  stirring  all  the  time.  Continue  this  until  the  alum 
no  longer  dissolves,  but  settles  to  the  bottom  of  the  beaker. 
The  solution  is  now  said  to  be  saturated.  Define  saturated  solu- 
tion. Your  beaker  now  contains  a  saturated  solution,  with  a 
little  of  the  undissolved  solid  as  a  sediment  in  the  bottom.  Put 
this  over  the  flame  of  the  Bunsen  burner  and  heat  it  until  it 
boils.  What  becomes  of  the  sediment? 
Is  cold  or  hot  water  capable  of  holding 
a  larger  amount  of  alum  in  solution? 
Make  a  very  strong  solution  of  alum  in 
water  and  pour  it  into  a  beaker  with  the 
end  of  a  string  hanging  down  into  it,  as 
shown  in  Fig.  26.  Let  the  beaker  stand 
for  a  day  or  two  until  part  of  the  solution 
evaporates.  Remove  the  string  from  the 
solution.  Describe  what  you  see.  What 
effect  have  cooling  and  evaporation  upon 
a  saturated  solution?  How  could  you 
separate  a  solid  in  solution  from  its 
solvent  ? 

Arrange  a  piece  of  apparatus  as  shown  in  Fig.  27.  Partly 
fill  the  bottle  with  a  saturated  solution  of  photographers'  hypo 
(sodium  hyposulphite).  Set  the  adjustable  pinchcock  so  that 
the  solution  will  drop  very  slowly  —  not  more  than  two  drops 
per  minute.  Allow  the  process  to  continue  for  several  days. 
Describe  and  explain  the  method  of  formation  of  the  material 
which  collects  on  the  glass  plate  below. 

Crush  to  powder  some  marble  in  a  mortar.  Put  some  of 
the  powder  in  a  small  beaker  and  fill  the  beaker  with  water. 
Let  this  stand  for  a  day  or  two.  Carefully  pour  off  the  water 
and  filter  it.  Boil  the  filtered  water  in  an  evaporating  dish, 
evaporating  it  to  dryness.  Do  you  find  any  residue  in  the 
evaporating  dish?  Is  marble  soluble  in  water?  Put  some  of 
the  powdered  marble  in  a  small  beaker  and  fill  the  beaker  with 
water.  Lead  a  tube  from  a  carbon  dioxide  generator  into  this 
beaker   of   water  and  let  the   gas  slowly  bubble  up  through 


Fig.  26.  A  Beaker  ar- 
ranged for  the  Forma- 
tion of  Crystals  of  Alum 


VEINS 


137 


the  water.  Continue  this  process  for  a  day  or  two.  Again 
pour  off  the  water,  filter,  and  evaporate  to  dryness.  Do 
you  find  any  residue 
in  the  evaporating 
dish?  Is  marble  solu- 
ble in  water  which  has 
carbon  dioxide  in  it? 
Water  with  carbon 
dioxide  is  responsible 
for  the  removal  of 
most  of  the  material 
in  the  making  of  cav- 
erns in  limestone. 

Examine  a  stalac- 
tite. Describe  shape, 
structure,  color,  and 
anything  else  worthy 
of  note.  Apply  a 
small  drop  of  hydro- 
chloric acid  to  the 
stalactite  and  describe 
the  result.  Efferves- 
cence is  a  proof  that 
it  has  lime  in  its  com- 
position. Describe 
the  process  of  the  formation  of  a  stalactite.  If  possible,  visit  a 
cavern  and  describe  what  you  see.  Illustrate  by  drawings 
or  photographs. 


Fig.  27.    A  Bottle  and  Sipliuu  anaiiged  for 
the  Formation  of  Stalactites 

Blow  into  the  open  tube  until  the  solution  flows  from 
the  siphon,  and  then  adjust  the  pinchcock 


EXERCISE  LIII 
VEINS 


How  are  rocks  fractured  ?  (See  Exercise  XXXI ;  also  Topic 
35,  Causes  of  Mountains,  p.  16,  and  Topic  62,  Earthquakes, 
p.  27.)  How  deep  into  the  earth  do  cracks  and  fissures  extend? 
Underground  water  may  follow  these  fissures  wherever  they 


138 


PHYSICAL  GEOGEAPHY  MANUAL 


go.  As  water  descends  to  great  depths  what  change  of  tempera- 
ture does  it  undergo  ?  What  effect  does  this  change  of  tempera- 
ture have  upon  its  ability  to  dissolve  rocks  ?  (See  Exercise  LII.) 
If  water  is  thoroughly  saturated  with  material  in  solution,  what 
effect  will  be  produced  by  cooling  it?  This  is  the  process  by 
which  cracks  and  fissures  in  the  rocks  are  filled.  What  materials 
may  be  dissolved  by  water?  Why  are  veins  of  interest  to  the 
miner?  Distinguish  between  the  manner  of  formation  of  veins 
and  dikes.     (See  Topic  61,  Volcanic  Phenomena,  p.  26.) 

Examine  veins  in  a  cliff  or  in  specimens  which  you  have  in 
the  laboratory.    What  kind  of  material  do  you  find  in  the  rock 


'Fig.  28.    A  liock  with  Intersecting  Veins 


which  contains  the  veins  ?  Of  what  kind  of  material  are  the  veins 
composed  ?  Wl^ich  is  harder,  the  veins  or  the  rock  in  which  they 
occur?  Which  will  wear  away  faster  when  subjected  to  the 
action  of  the  weather?  Give  the  width  of  the  widest  vein  which 
you  find;  of  the  narrowest.  Are  the  veins  which  you  find  in 
any  one  cliff  of  equal  age  ?    Give  reason  for  your  answer. 

Illustrate  by  drawings  what  you  see,  showing  as  many  facts 
as  possible  about  veins. 


DENSITY  AND  TEMPERATURE  OF  SEA  WATER     139 


EXERCISE  LIV 

DENSITY  AND  TEMPERATURE  OF  SEA  WATER 

Part  I 

Weigh  accurately  about  100  grams  of  sea  water.  Boil  and 
evaporate  to  dryness.  Weigh  the  residue  and  calculate  the  per- 
centage of  solid  matter.  From  the  books  determine  what  part 
of  the  solid  matter  is  common  salt  (chloride  of  sodium).  Accord- 
ing to  this,  how  much  common  salt  in  100  pounds  of  sea  water? 

Part  II 


Temperature 

Density 

Bay 

Ocean 

Bay 

Ocean 

July 

January     

77 
58.5 

68 
60 

1.0238 
1.0245 

1.0228 
1.0230 

The  accompanying  table  gives  the  temperature  and  density 
of  the  water  in  San  Diego  bay  and  in  the  open  sea  for  July  and 
Januaiy.  In  which  is  the  water  warmer  during  the  month  of 
July?  Account  for  this.  In  which  is  it  warmer  in  January? 
Account  for  this.  In  which  is  the  temperature  more  nearly 
uniform  throughout  the  year?  According  to  this  table,  is  the 
water  denser  in  the  bay  or  in  the  ocean?  The  density  of  the 
water  in  the  Red  sea  and  in  the  Mediterranean  sea  is  said  to  be 
from  1.027  to  1.028.    Account  for  this  great  density. 

Part  III 

According  to  the  table  in  Part  II,  is  the  water  denser  when 
it  is  warm  or  when  it  is  cold  ?  Which  has  greater  density,  water 
or  ice?  How  do  you  know?  (See  Exercise  XXXI.)  Suppose 
ice  should  sink  upon  freezing.  How  would  this  affect  its  rate 
of  melting  under  the  influence  of  the  sun?  How  might  this 
affect  the  climate  of  a  region  near  a  large  lake  of  fresh  water? 


140  PHYSICAL   GEOGEAPHY  MANUAL 

EXERCISE  LV 
TIDES 

Refer  to  the  United  States  tide  tables,  select  some  port,  and 
note  the  times  and  heights  of  tides  for  a  period  of  one  month  or 
more.  In  what  units  are  the  heights  of  tides  given  ?  From  what 
is  the  height  of  a  tide  reckoned  ? 

Use  cross-section  paper.  Draw  a  line  lengthwise  through  the 
center  of  the  sheet  to  represent  mean  lower  low  water.  Use 
vertical  distances  to  represent  the  heights  of  the  tides,  scale 
1  centimeter  to  1  foot.  Use  horizontal  distances  to  represent 
time,  scale  1  millimeter  to  6  hours.  Use  lead  pencil  and  place 
a  dot  at  the  proper  point  to  represent  the  time  and  height  of 
each  of  the  four  tides  for  the  first  day  of  your  observations. 
Use  ink  and  connect  these  points  consecutively,  making  a 
straight  line  from  each  to  the  one  immediately  following.  Do 
the  same  for  the  following  day  and  proceed  in  a  similar  manner 
with  all  data  for  the  time  of  observation. 

How  far  in  feet  is  mean  lower  low  water  below  mean  sea 
level  ?  (See  the  note  at  the  bottom  of  the  page  in  the  tide  table.) 
Draw  a  line  to  represent  mean  sea  level.  By  referring  to  the 
almanac  determine  the  dates  of  the  moon's  phases  during  the 
time  of  observations  of  the  tides.  On  the  horizontal  line  just 
above  the  highest  high  tide  make  drawings  to  represent  these 
different  phases  of  the  moon,  being  careful  to  get  them  in  the 
spaces  for  the  correct  dates.    Give  your  diagram  a  title. 

At  what  phase  of  the  moon  are  the  tides  highest  ?  At  what 
phase  are  they  lowest  ?  At  what  phase  do  the  tides  have  great- 
est range  ?  What  name  is  given  to  these  tides  ?  At  what  phase 
of  the  moon  do  the  tides  have  least  range  ?  What  name  is  given 
to  these  tides?  Make  drawings  to  show  the  positions  of  the 
earth,  the  sun,  and  the  moon  at  the  time  of  greatest  range  of 
tides ;  at  the  time  of  least  range  of  tides.  What  causes  tides  ? 
How  do  you  know  ? 


141 


142  PHYSICAL  GEOGEAPHY  MANUAL 

EXERCISE  LVI 
OCEAN  CURRENTS 

Observe  the  pilot  chart  of  the  North  Atlantic  ocean.  How  is 
the  direction  of  the  ocean  currents  indicated  ?  (See  the  explana- 
tion near  the  lower  left-hand  corner  of  the  map.)  What  is  the 
direction  of  the  current  at  each  of  the  following  points  :  (1)  south- 
west of  the  Cape  Verde  islands,  16  degrees  north,  25  degrees  west? 
(2)  on  the  equator  off  the  east  coast  of  South  America  ?  (3)  from 
10  to  20  degrees  north  latitude  in  the  Pacific  ocean  ?  Compare 
these  directions  with  the  directions  of  the  prevailing  winds  at 
these  points,  as  given  by  the  pilot  charts.  Compare  the  courses 
of  the  ocean  currents  of  the  world  with  the  directions  of  the 
prevailing  winds,  as  shown  by  the  maps.  Fig.  29  and  Fig.  30. 
What  do  the  books  give  as  the  cause  of  ocean  currents  ? 

What  is  the  direction  of  the  current  in  the  Caribbean  sea? 
in  the  Atlantic  ocean  between  Florida  and  the  Bahamas?  What 
name  is  given  to  this  current?  What  is  the  direction  of  this 
current  in  the  Atlantic  ocean  at  a  point  40  degrees  north  and 
50  degrees  west?  Trace  this  current  still  further  and  describe 
its  general  shape  east  of  this  point.  What  is  the  direction  of 
the  current  off  the  east  coast  of  Labrador  and  Newfoundland  ? 
Trace  this  current  along  the  coast  as  far  as  you  can.  Is  it  a 
warm  or  a  cold  current?  What  effect  does  it  have  on  the  tem- 
perature of  the  east  coast  of  the  United  States?  What  finally 
becomes  of  this  current?  Trace  with  a  pointer  the  main  cur- 
rents of  the  North  Pacific  ocean.  Describe  their  general  shape. 
See  the  small  black  figures  giving  knots  per  hour,  and  give  the 
velocity  of  the  current  in  the  region  of  northeast  trades,  130 
degrees  west ;  in  mid-ocean  south  of  the  Aleutian  islands ;  off 
the  west  coast  of  Oregon. 

Do  you  find  indications  in  the  Pacific  ocean  of  a  cold  current 
from  the  Arctic  regions  ?  What  do  you  know  of  the  tempera- 
ture of  Vladivostok?  (See  Fig.  4.)  Compare  its  temperature 
in  winter  with  that  of  Portland,  Oregon.  Compare  the  latitude 
of  these  two  places. 


o  a 


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oa    .3 


143 


144  PHYSICAL   GEOGKAPHY  MANUAL 

EXERCISE  LVII 
ICEBERGS 

Put  a  piece  of  ice  in  a  vessel  of  cold  water.  Why  does  it  float  ? 
Which  is  heavier,  a  cubic  foot  of  ice  or  a  cubic  foot  of  water? 
Define  density.    Which  has  the  greater  density,  ice  or  water? 

Push  the  ice  down  so  that  it  is  entirely  under  water.  Does 
it  resist  your  pressure  ?  The  force  that  tends  to  lift  it  up  is 
called  the  buoyant  force  of  water.  Suppose  that  a  glacier  is  pass- 
ing down  a  slope  into  the  sea,  so  that  the  lower  part  is  immersed 
in  water.  What  force  is  thrusting  it  down  into  the  sea?  What 
force  is  tending  to  lift  it  up  ?  Explain  how  icebergs  are  formed 
from  such  a  glacier. 

About  what  proportion  of  the  floating  ice  is  under  water? 
Does  it  float  with  the  broadest  surface  up  or  down  ?  Turn  it 
over  and  see  if  you  can  make  it  float  in  another  position.  In 
how  many  positions  can  you  make  it  float  ?  Suppose  one  side 
should  melt  away.  What  effect  would  this  probably  have  upon 
the  position  of  the  ice  in  the  water?  Account  for  an  iceberg's 
turning  over  in  the  sea. 

To  find  what  proportion  of  a  floating  object  is  beneath  the 
surface,  divide  its  specific  gravity  by  the  specific  gravity  of 
the  liquid.  Dryer  {Lessons  in  Physical  Geograjjliy^  p.  255)  gives 
the  specific  gravity  of  sea  water  as  from  1.024  to  1.03,  when 
at  the  temperature  of  60  degrees.  The  specific  gravity  of  sea 
ice  is  also  given  as  .9175.  Using  the  specific  gravity  first  given 
for  sea  water,  calculate  what  proportion  of  an  iceberg  is  under 
water.  Do  the  same,  using  the  second  specific  gravity  which  is 
given  above.  What  proportion  is  above  water  in  each  case  ?  Why 
should  more  than  one  specific  gravity  be  given  for  sea  water? 

Where  do  most  of  the  icebergs  of  the  North  Atlantic  ocean 
originate?  What  is  the  fate  of  those  that  float  south?  How 
far  south  do  they  ever  go?  Describe  the  location  of  the  line 
marking  the  limit  of  floating  ice  in  the  North  Atlantic.  (See 
Fig.  30.)  What  is  the  principal  danger  to  ships  cruising  among 
icebergs  ? 


THE  SEA  A^^D  MAN  145 

EXERCISE  LVIII 

THE  SEA  AND  MAN 

Part  I 

Use  a  globe  and  string;  place  the  string  on  the  surface  of 
the  globe  so  as  to  connect  with  the  shortest  line  the  Galapagos 
islands  and  the  island  of  Borneo.  In  which  direction  does  this 
line  extend?  With  what  important  mathematical  line  on  the 
earth's  surface  does  it  almost  coincide?  If  your  string  were 
extended  so  as  to  make  a  complete  circle  round  the  earth, 
would  it  make  a  great  or  a  small  circle? 

San  Francisco  and  Yokohama  are  in  almost  the  same  latitude. 
Connect  these  points  on  the  globe  with  a  string  in  such  a  way 
as  to  make  the  shortest  line  between  them.  In  what  direction 
does  the  line  pass?  Near  what  points  on  the  earth's  surface 
does  it  pass  ?  If  this  line  were  extended  so  as  to  make  a  complete 
circle  round  the  earth,  would  it  make  a  great  or  a  small  circle  ? 
Does  this  circle  coincide  with  any  circle  of  latitude  ?  Compare 
this  shortest  line  which  you  have  drawn  between  San  Francisco 
and  Yokohama  with  the  route  actually  taken  by  steamships 
plying  between  these  two  ports,  as  shown  on  the  pilot  chart 
of  the  North  Pacific  ocean.  How  would  you  find  the  shortest 
line  between  any  two  points  on  the  earth's  surface  ? 

Part  II 

Heat  equal  weights  of  water  and  rock  to  the  same  tempera- 
ture. Place  them  aside  and  allow  them  to  cool.  Which  cools 
more  quickly  ?  Cool  equal  weights  of  water  and  rock  to  a  low 
temperature  and  place  them  in  the  direct  sunlight.  Which  heats 
more  quickly?  Which  gets  hotter  in  summer,  land  or  water? 
Which  is  more  nearly  uniform  in  temperature  throughout  the 
year?  What  effect  does  this  fact  have  upon  the  climate  of 
places  near  the  sea  or  near  a  large  lake? 


o 


o 


146 


THE   SEA  AND  MAN 


147 


Part  III 

Slowly  boil  a  flask  of  sea  water  and  condense  the  steam  by 
passing  it  through  a  tube  inclosed  in  a  jacket  of  cold  water. 
Taste  the  condensed  vapor.  Do  you  find  salt  in  it?  Ocean 
steamships  are  so  equipped  that  they  can  supply  drinking  water 


Fic.  32.    The  Rocky  Headland  shown  in  the  Distance  in  Fig.  31 
The  detached  rock  island  is  called  Sugar  Loaf 

from  sea  water  by  distillation.  Is  water  vapor  which  rises  from 
the  sea  salt  or  fresh?  If  rain  water  were  salt,  how  would  vege- 
tation be  affected?  How  does  evaporation  affect  the  density 
of  the  water  in  the  sea  ?  Name  some  bodies  of  water  in  which 
this  is  specially  noticeable. 


Part  IV 

Make  a  list  of  food  products  which  are  obtained  from  the 
sea.  Make  a  list  of  other  useful  articles  which  are  obtained 
from  the  sea. 


148 


PHYSICAL  GEOGKAPHY  MAIS  UAL 


EXERCISE  LIX 

HEADLANDS,  BEACHES,  SEA  CAVES 

Fig.  31  is  a  picture  of  Avalon  bay,  Santa  Catalina  island, 
southern  California.  Fig.  32  is  a  detail  of  the  same,  showing 
the  rocky  headland  at  one  side  of  the  bay.  Observe  the  bowlders 
lying  in  the  foreground.  Describe  shape  and  size.  What  effect 
will  action  of  the  waves  have  upon  the  shape  and  size  of  these 


Ik..  So.    Sea  Caves  at  La  Jolla  (pronounced  la-ho-yah),  Coast  of 
Southern  California 

The  cliff  is  sandstone 

bowlders  ?  How  will  the  waves  accomplish  this  ?  Compare  these 
bowlders  with  those  shown  in  Fig.  38  and  account  for  the  dif- 
ference. What  will  finally  be  the  fate  of  any  bowlders  con- 
stantly subjected  to  the  action  of  the  waves  ?  After  the  advance 
of  a  wave  its  waters  return  to  the  sea,  bearing  some  rock  waste 
with  them.    Rock  waste  of  what  sizes  can  be  carried  most  readily 


HEADLANDS,  BEACHES,  SEA  CAVES 


149 


by  the  waves  ?    What  disposition  will  the  sea  make  of  material 
thus  removed  from  the  shore  ? 

What  agencies  probably  removed  from  the  cliff  the  bowl- 
ders shown  in  Fig.  32  ?  In  times  of  storm  the  waves  have 
sufficient  force  to  pick  up  bowlders  and  bear  them  along,  thus 
hurling  them  against  the  cliff.  Which  would  probably  prove 
the  more  destructive  agent,  waves  alone  or  waves  armed  with 
bowlders,  pebbles, 
and  sand?  Ob- 
serve the  rock 
island,  Sugar  Loaf. 
It  has  been  de- 
tached from  the 
mainland  by  the 
attack  of  the  sea. 
Predict  the  effects 
which  the  sea  will 
yet  produce  upon 
the  mainland. 
Fig.  33  shows  a 
sandstone  cliff'  at 
La  Jolla  on  the 
coast  of  southern 
California.  De- 
scribe the  effects 


Fig.  34.    An  Arch  cut  by  Waves 


which  the  waves  have  produced  here.  Why  has  their  attack 
been  more  effective  in  some  parts  of  the  cliff  than  in  others? 
Sometimes  fantastic  forms  result  from  the  action  of  waves. 
Tell  what  you  see  in  Fig.  34.  What  structure  of  the  rocks 
makes  this  arch  possible? 

What  condition  of  sea  bottom  is  necessary  to  produce  break- 
ers ?  (See  Topic  82,  Waves,  p.  35.)  Judging  from  the  fact  that 
but  one  breaker  appears  on  the  shore  in  Fig.  32,  would  you 
think  the  sea  is  deep  or  shallow  ?  Is  this  characteristic  of  strong 
or  weak  coasts?  Which  part  of  the  bay  in  Fig.  31  has  the 
strongest  coast?    Which  the  weakest?    This  bay  is  what  the 


150 


PHYSICAL  GEOGRAPHY  MANUAL 


books  sometimes  call  a  pocket  beach.    What  can  you  see  that  is 
appropriate  in  this  name?    It  is  sometimes  called  a  crescent 

beach.  Is  this  name 
equally  appropriate? 
What  difference  would 
you  expect  to  find  in 
the  size  and  the  shape 
of  the  rock  waste  at 
the  headland  and  mid- 
way between  the  two 
headlands  ? 

If  possible  visit  the 
coast.  Observe  sea 
cliffs,  headlands,  bowl- 
ders, pebbles,  sand, 
beaches,  sea  caves,  bars, 
spits,  marshes,  sea- 
weed, and  other  life 
along  the  shore,  and 
anything  else  that  you 
consider  worthy  of 
note.  Make  a  map  of 
the  region  which  you 
have  visited  and  let 
Illustrate  with  photo- 


FiG.  35.  Map  of  Sand  Reefs  off  the  Coast 
of  North  Carolina 

your  description  be  as  full  as  possible, 
graphs  or  drawings  whenever  possible. 


EXERCISE  LX 


BARRIER  BEACHES 

Locate  Atlantic  City  on  a  map  of  the  United  States.  How 
far  and  in  what  direction  is  it  from  New  York  city  ?  Refer  to 
the  Atlantic  City  (N.J.)  sheet.  (Topographic  map  of  the  United 
States  Geological  Survey.)  How  much  of  the  region  shown 
on  this  sheet  is  mainland?  How  high  is  it  above  sea  level? 
Describe   the  barrier  beaches,  giving  their  distance  from   the 


BARRIER  BEACHES 


151 


mainland,  direction  of  trend  with  reference  to  the  mainland, 
height  above  sea  level,  width,  and  general  shape.  Compare 
them,  in  all  respects  named  above,  with  the  barrier  beaches  and 
bars  represented  on  the  map  of  the  Atlantic  coast  from  Beach 
Haven  to  Sandy  Hook.  (See  the  large  map.^)  Also  make  a  com- 
parison of  these  beaches  and  the  bars  or  reefs  represented  on 
the  maps  of  the  coasts 
of  North  Carolina  and 
southwestern  Texas. 
(See  Figs.  35  and  36.) 

How  does  the  land 
lie  between  Atlantic 
City  and  the  main- 
land ?  Describe  the 
position  of  bays,  chan- 
nels, and  "thorofares." 
Are  these  bodies  of 
water  becoming  deeper 
or  shallower  ?  Give 
reason  for  your  answer. 
What  will  finally  be 
their  fate  ?  What  pre- 
vents the  inlets  from 
becoming   filled   with 

sand?  (Read  the  description  in  Folio  1.)  How  is  it  possible 
to  build  railroads  across  this  region?  For  what  is  Atlantic 
City  famous?  In  what  respects  is  it  well  located?  Do  you 
think  of  any  disadvantages  due  to  its  location? 

Almost  the  entire  region  around  Provincetown  (Mass.)  has 
been  built  up  by  the  sea.  (See  the  large  map.^)  What  do  you 
think  is  the  character  of  the  soil  ?  Whalj  evidence  of  the  exist- 
ence of  dunes  do  you  find  on  this  map  ?  What  is  done  to  check 
the  migration  of  dunes  ?  (See  the  government  reports.)  What 
use  have  men  made  of  the  peculiar  shape  of  the  coast  line  at 

1  Assembled  topographic  sheets  of  the  United  States  Greological  Survey,  as 
shown  on  p.  170. 


Fig.  36.    Sand  Reefs  off  the  Coast  of  Texas 


152  PHYSICAL  GEOGRAPHY  MANUAL 

Provincetown  ?  Do  you  think  good  harbors  could  be  made  on 
the  east  side  of  Cape  Cod  peninsula?  Give  reason  for  your 
answer. 

EXERCISE  LXI 

DROWNED  AND  ELEVATED  COASTS 

Refer  to  the  Boothbay  (Maine)  sheet.  (See  topographic  map 
of*  the  United  States  Geological  Survey.)  This  sheet  represents 
a  drowned  coast.  What  does  this  mean  ?  Describe  the  shape  of 
the  inlets  and  the  projecting  lands.  Measure  the  length  of  the 
coast  in  a  straight  line  from  Griffith  Head  to  Pemaquid  Point. 


Fig.  37.    Terraces  cut  by  the  Sea  at  Point  San  Pedro,  California, 
showing  a  Rising  Coast 

Estimate  the  length  of  coast  line  between  these  two  points,  pass- 
ing around  the  bays  but  not  entering  the  broad  rivers.  Char- 
acterize this  coast  line  as  straight  or  crooked.  What  land  forms 
would  result  if  Linekin  neck  should  sink  100  feet?  Are  islands 
common  on  drowned  coasts  ?  What  is  the  shape  of  the  islands 
represented  on  this  map  ?  of  the  hills  ?  Is  there  a  general  trend 
of  the  land  forms?  If  so,  in  what  direction?  How  is  this 
accounted  for?    (See  p.  4  of  Folio  1.) 


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o      8 

o    2 


^    .a 


153 


164  PHYSICAL  GEOGRAPHY  MANUAL 

Has  this  region  known  more  of  erosion  or  more  of  deposi- 
tion recently?  Why  was  the  surface  eroded  more  deeply  in 
some  places  than  in  others  ?  Are  the  rocks  now  composing  the 
ridges  probably  hard  or  soft?  Give 'reason  for  your  answer. 
Why  is  it  appropriate  to  call  this  a  "stern  and  rock-bound 
coast "  ? 

It  is  said  that  a  former  channel  of  the  Hudson  river  can  be 
traced  through  New  York  bay  several  miles  out  into  the  ocean. 
What  does  this  indicate  as  to  the  movement  of  the  land  at  New 
York  ?  Name  another  river  on  the  Atlantic  coast  that  has  been 
drowned.  Do  drowned  coasts  always  produce  fiords  ?  When  do 
they  not  ?  Of  what  use  to  men  are  fiords  and  drowned  rivers  ? 
Name  two  notable  examples  of  drowned  rivers  on  the  Pacific 
coast.  What  has  been  the  movement  of  the  land  along  the  coast 
of  southern  California?  (See  Figs.  37  and  38.)  Describe  what 
you  see  in  Fig.  38.  How  many  elevated  beaches  or  former  shore 
lines  can  you  count  in  Fig.  37  ?  Compare  the  shape  of  the  coast 
line  from  San  Diego  to  San  Pedro  (Cal.)  with  that  of  the  coast 
of  Maine.  How  do  rising  coasts  usually  differ  from  sinking 
coasts  ? 

EXERCISE  LXII 
HARBORS 

Compare  the  number  of  natural  harbors  on  the  Atlantic  coast 
of  the  United  States  north  of  Virginia  with  the  number  from 
Virginia  to  Florida.  Account  for  the  difference  in  number. 
How  has  the  number  of  good  harbors  affected  the  growth  of 
cities  in  the  two  regions  ? 

What  natural  features  have  been  utilized  to  form  a  harbor  at 
New  York  (see  map  if  necessary)?  at  Philadelphia?  at  Boston? 
at  New  Orleans ?  at  San  Francisco?  at  Seattle  and  Tacoma? 
at  Manila  ?  at  Liverpool  ?  Do  you  know  of  other  natural  features 
which  make  good  harbors  ? 

Do  you  know  of  a  port  with  an  artificial  harbor?  What  are 
some  of  the  methods  used  in  building  artificial  harbors  ?  Define 
breakwater;  dredge. 


ECONOMIC  MINERALS  AND  ORES  155 

EXERCISE  LXIII 
ECONOMIC  MINERALS  AND  ORES 

The  streak  of  a  mineral  is  the  color  of  its  powder. 

Some  minerals  are  much  harder  than  others.  A  series  of  ten 
has  been  selected,  running  from  the  softest  to  the  hardest.  This 
is  called  the  scale  of  hardness.  The  hardness  of  rocks  is  usually 
given  by  number.    Following  is  the  scale  : 

1.  Talc.  Very  soft,  can  be  scratched  easily  with  the  finger  nail, 

2.  Gypsum.  Can  be  scratched  with  the  finger  nail,  but  not 
as  easily  as  talc. 

3.  Calcite.  Cannot  be  scratched  with  the  finger  nail.  Easily 
scratched  with  the  point  of  a  knife. 

4.  Fluorite.    Scratched  with  a  knife,  but  not  easily. 

5.  Apatite.    Not  so  easily  scratched. 

6.  Orthoclase.  Can  be  scratched  with  difficulty  with  a  knife 
blade.    It  will  scratch  glass. 

7.  Quartz.  Cannot  be  scratched  Avith  a  knife.  It  will  scratch 
glass. 

8.  Topaz.    Cannot  be  scratched  by  quartz. 

9.  Corundum.    Harder  than  topaz. 

10.  Diamond.  The  hardest  mineral. 

Examine  each  of  the  following  minerals :  pyrite,  magnetite, 
hematite,  limonite,  cuprite,  chalcopyrite,  malachite,  azurite, 
galenite  (lead),  gold,  gypsum,  Jisbestos,  halite  (salt),  calcite. 
(The  first  four  are  forms  of  iron.  The  second  four  are  forms  of 
copper.)    Make  and  fill  a  table  similar  to  the  accompanying  one. 

1.  Name  of  specimen. 

2.  Use. 

3.  Where  found  in  the  United  States. 

4.  Color. 

5.  Streak. 

6.  Hardness. 

7.  Specific  gravity.  (Do  not  attempt  to  find  the  specific 
gravity  of  salt.) 

8.  Remarks. 


156 


PHYSICAL  GEOGKAPHY  MANUAL 


If  possible,  visit  one  or  more  of  the  following  places  and 
write  an  account  of  what  you  see:  (1)  a  mine;  (2)  a  smelter; 
(3)  a  foundry ;  (4)  a  shot  tower ;  (5)  a  mint ;  (6)  salt  works. 

Note.  Apply  hydrochloric  acid  to  calcite  and  describe  the  result.  What 
other  specimen  have  you  had  which  acts  in  this  way  when  hydrochloric 
acid  is  applied?  (See  Exercise  LII.)  Calcite  is  the  essential  constituent 
of  this  rock,  as  it  is  of  limestone  and  marble. 

EXERCISE  LXIV 


LIMESTONE 

Describe  coquina  limestone.  Tell  where  it  comes  from.  How 
do  you  suppose  it  was  formed  ?  Describe  the  specimen  of  fos- 
siliferous  limestone.  Tell  where  it  comes  from.  Make  a  draw- 
ing of  one  of  the 
fossils.  Give  your 
drawing  a  title. 
Draw  or  describe 
different  varieties 
of  coral.  Where 
are  corals  found  ? 
Are  they  found  in 
sufficiently  large 
quantities  to  be 
counted  as  build- 
ers of  rocks?  (See 
Fig.  39.)  Do  you 
know  of  other  fos- 
sils which  make 
limestone  ?  If  so, 
describe  or  draw 
them.  Limestone 
has  been  called 
the  graveyard  of  the  sea.  What  is  there  in  this  name  which  is 
appropriate?  Where  is  chalk  found?  Describe  color,  texture, 
hardness,  use. 


^^^^^^^^^^^^^^^^^V^^^^^l 

PI 

i^J 

Fig.  39.    A  Church  built  of  Coral,  at  Laliaina, 
Hawaiian  Islands 


COAL  157 

Distinguish  between  cJialk  and  crayon.  Test  limestone  with 
hydrochloric  acid.  What  mineral  have  you  proved  to  be  pres- 
ent? (See  Exercise  LXIII.)  This  mineral  is  the  essential  con- 
stituent of  limestone.  Add  acid  to  a  very  small  piece  of 
limestone  or  to  a  small  quantity  of  powdered  limestone  until 
all  effervescence  ceases.  Does  the  rock  entirely  disappear?  If 
not,  it  is  not  pure  limestone.  How  do  you  account  for  the 
presence  of  impurities  ? 

What  is  limestone  used  for?  What  gas  is  obtained  from 
limestone?  How  is  this  gas  sometimes  used?  Apply  the  acid 
test  to  marble.  How  does  marble  differ  in  appearance  from 
limestone  ?  Do  you  find  any  fossils  in  marble  ?  How  may  fos- 
sils disappear  from  a  rock  while  it  is  still  underground  ? 

EXERCISE  LXV 
COAL 

Examine  peat.  Give  color.  Make  a  mental  estimate  of  its 
specific  gravity,  and  record.  Describe  the  structure  of  peat. 
Give  a  theory  of  its  formation,  either  your  own  or  that  of  the 
books.  If  your  own,  give  reasons  for  adhering  to  this  theory ; 
if  not  your  own,  state  where  you  got  it.  Of  what  value  is  peat? 
Where  did  this  specimen  come  from?  Do  you  know  of  any 
near  your  home? 

Examine  coal.  Give  color.  Estimate  specific  gravity  and 
compare  with  that  of  peat.  Do  you  find  any  evidence  of  the 
existence  of  vegetable  matter  in  coal  ?  If  so,  draw  one  or  more 
forms  which  you  see.  Give  your  drawing  a  title.  How  do  the 
books  explain  the  formation  of  coal?  In  what  parts  of  the 
United  States  is  it  found?  In  what  part  is  it  found  in  largest 
quantities  ?  Name  two  or  three  kinds  of  coal  and  compare  their 
values  for  fuel.  From  what  places  does  your  local  supply  of 
coal  come?    Which  is  considered  best ?    Why? 

Describe  color,  structure,  and  "  feel "  of  graphite.  Where  is  it 
found?    For  what  is  it  used?    Graphite  is  made  up  of  carbon. 


158 


PHYSICAL  GEOGRAPHY  MANUAL 


Carbon  is  found  in  both  coal  and  peat.    It  is  also  found  in  the 
leaves  and  stems  of  plants  and  trees. 

Put  a  piece  of  peat  on  a  metal  plate  and  heat  it  slowly  over 
the  Bunsen  burner.  What  change  in  color  do  you  note  ?  The 
most  common  color  of  carbon  is  black.  Peat  is  often  some  color 
other  than  black  because  constituents  are  present  other  than 
carbon.  The  heat  drives  off  these  constituents  and  there  remains 
little  but  carbon.  Why  is  a  charred  stick  of  wood  black?  Apply 
heat  to  the  piece  of  peat  until  it  glows,  and  allow  it  to  remain 


Fig.  40.    A  Petrified  Tree  spanning  a  Gulch  in  the  Petrified  Forest  of 
Arizona.    (See  Topic  98,  Fossils,  p.  41) 

thus  for  several  minutes.  What  change  do  you  note?  What 
constituent  of  the  atmosphere  is  probably  uniting  with  the 
peat?  (See  Exercise  XL)  Carbon  is  found  in  all  fuel,  includ- 
ing kerosene,  gasoline,  and  gas.  What  constituent  of  the  air 
unites  with  it  when  it  burns  ?  This  forms  carbon  dioxide. 
What  do  you  know  about  the  healthfulness  of  this  gas?  Did 
you  ever  hear  of  a  person  being  suffocated  from  the  fumes  of  a 
smoldering  fire?  Why  should  a  gas  or  oil  stove  be  connected 
with  the  flue? 


GEANITE  159 

What  is  the  color  of  the  soil  in  a  bog?  Where  does  the 
coloring  matter  probably  come  from  ?  Black  slate  owes  its  color 
to  carbon.  Pulverize  and  heat  intensely  hot  a  small  amount  of 
black  slate,  thus  burning  out  the  carbon.  What  is  the  color  of 
the  powder  which  remains?  If  it  is  red  or  broAvn,  what  other 
mineral  was  probably  present  in  the  slate  ?    (See  Exercise  XI.) 


EXERCISE  LXVI 

GRANITE 

Part  I 

Examine  specimens  of  granite,  quartz,  feldspar,  mica,  horn- 
blende.   Make  and  fill  a  table  similar  to  the  following. 

1.  Name  of  specimen. 

2.  Color. 

3.  Hardness. 

4.  Structure.        < 

5.  Use. 

6.  Other  kinds, 

7.  Remarks. 

How  can  you  distinguish  between  calcite  and  quartz?  be- 
tween quartz  and  feldspar?  between  feldspar  and  hornblende? 
between  feldspar  and  mica?  between  mica  and  gypsum  of  the 
selenite  variety  ?    (Note  the  elasticity  of  the  flakes.) 

When  pure  feldspar  decays  it  makes  a  very  fine  clay  called 
kaolin.  Examine  and  describe  kaolin.  How  can  you  distinguish 
between  kaolin  and  chalk? 

Part  II 

Examine  and  describe  the  surface  of  a  freshly  fractured  piece 
of  granite.  Give  color,  structure,  and  components  of  the  piece 
which  you  have.  Which  component  is  found  in  greatest  abun- 
dance? Which  least  abundantly?  Is  granite  found  near  your 
home  ? 


160  PHYSICAL  GEOGRAPHY  MANUAL 

Examine  crumbling  granite.  How  many  and  what  compo- 
nents can  you  discover?  How  does  this  specimen  differ  from 
solid  granite  ?  What  component  seems  to  have  suffered  greatest 
decay?  Put  a  small  amount  of  highly  decomposed  granite  in 
water.  Which  components  settle  to  the  bottom?  Which  com- 
ponent makes  the  water  muddy?  Which  component  is  practi- 
cally indestructible  ?  What  becomes  of  all  of  the  grains  of  this 
material  when  granite  decays?  Look  for  small  grains  of  mica 
in  the  sand  of  a  flowing  stream.  Does  decomposed  granite  make 
good  soil  ?    Does  decomposed  feldspar  make  good  soil  ? 


EXERCISE  LXVII 
FRAGMEXTAL  ROCKS 

Describe  size  and  shape  of  the  fragments  composing  breccia. 
These  fragments  lay  at  the  base  of  a  cliff.  Water  seeping  from 
the  face  of  the  cliff  percolated  through  them.  What  do  you 
suppose  that  had  to  do  with  the  process  of  cementing  the  frag- 
ments together?  Test  and  name  the  mateiial  forming  the 
cement.    Are  all  the  interstices  filled  ?    Look  closely  for  crystals. 

Examine  the  pebbles  from  the  beach.  Describe  size,  color, 
shape.  Compare  the  shape  with  the  shape  of  the  fragments  of 
breccia  and  account  for  the  difference. 

Examine  the  cementing  material  between  the  fragments  of 
the  conglomerate.  Do  you  find  evidence  of  the  presence  of  iron 
in  the  cement  of  any  of  the  specimens  of  conglomerate?  If  so, 
what  evidence  ?  Test  the  cement  for  lime  and  record  the  result. 
Compare  the  fragments  of  conglomerate  with  the  pebbles  exam- 
ined above. 

Examine  and  describe  color  and  structure  of  sandstone. 
Determine,  if  possible,  of  what  kind  of  fragments  it  is  com- 
posed. The  common  cements  in  sandstone  are  lime,  iron,  and 
clay.  In  which  of  your  specimens  do  you  find  lime  as  a  cement? 
In  which  iron  ?  In  which  clay  ?  In  which  do  you  find  two  kinds 
of  cement  present  ? 


Fig.  41.    A  Young  Fir  Tree  growing  from  a  Crack  in  a  Mass  of  Granite 


p^ 

n 

* '  ''^'^'M{ 

,,^v^ 

:  .r.t^ 

1 

vi^*  V  .^'''^ 

JkS^t'^  ■ 

r^SASdE^^^^^ 

n^mm 

^,^..<f 

^i^ 

^^cJg^ 

-«-     .._--., 

J^j 

-'M 

lil^ 

^WS^MML 

"'--*'"^l 

;?^^4SS^ 

'  ■''■'W^^ 

' 

% 

"^ 

Fig.  4:i.    A  Weir  ou  tlie  Truckee  River,  Nevada,  for  measuring 
Water  used  for  Irrigation 


161 


162 


PHYSICAL  GEOGRAPHY  MANUAL 


Shale  is  a  fragmental  rock.  Can  you  readily  see  the  frag- 
ments ?  Account  for  the  color  of  the  specimen  which  you  have. 
(See  Exercise  LXV.) 

Fragmental  rocks  are  usually  built  under  the  water,  and  the 
materials  of  which  they  are  composed  are  furnished  by  rivers 
and  by  the  action  of  waves.    Which  of  the  fragmental  rocks 


Fig.  43.    A  Flume  near  Redlauds,  Califoi-nia,  used  for  carrying  Water 
for  Irrigation  from  Bear  Lake.    (See  Fig.  22) 


would  probably  be  formed  nearest  the  shore?  Which  is  com- 
posed of  materials  that  the  water  would  carry  farthest  before 
depositing  them?  Arrange  the  fragmental  rocks  in  a  series, 
putting  that  first  which  was  deposited  nearest  the  shore  and 
the  others  in  the  order  of  their  deposition. 


BUILDING  STONE  163 

EXERCISE  LXVIII 
BUILDING  STONE 

What  kinds  of  stone  are  used  for  building  in  your  vicinity  ? 
Which  is  considered  best?  Why?  Are  the  same  kinds  used  for 
foundations?  If  not,  why?  What  kinds  are  used  for  interior 
decoration  ?  Could  these  be  used  for  exterior  decoration  as  well  ? 
Which  of  these  rocks  are  quarried  or  obtained  near  your  home  ? 
Where  do  the  others  come  from  ? 

How  is  slate  used  in  building?  Could  granite  be  used  for 
the  same  purpose  ?  Give  reason  for  your  answer.  If  blocks  of 
stratified  rocks  were  to  be  used  in  a  wall,  should  they  be  placed 
with  the  layers  horizontal  or  vertical  ?    Why  ? 

Did  you  ever  see  an  old  stone  building  with  the  surfaces 
of  the  stones  crumbling  ?  Why  do  they  crumble  ?  What  kind 
of  building  stone  crumbles  least?  Why?  Is  a  dry  or  a  moist 
climate  more  favorable  for  the  preservation  of  a  stone  build- 
ing? Do  vines  clinging  to  the  surface  of  a  stone  wall  cause 
the  wall  to  weather  more  or  less  rapidly  than  it  otherwise 
would  ? 

Examine  the  following  rocks:  granite,  red  sandstone,  gray 
sandstone,  limestone,  marble,  slate.  Make  and  fill  a  table  simi- 
lar to  the  following.  (In  addition  to  your  observations,  seek 
information  from  property  owners,  contractors,  stone  masons, 
and  others.) 

1.  Name  of  stone. 

2.  Color. 

3.  Ease  with  which  it  can  be  worked. 

4.  Durability. 

5.  Use. 

6.  Source  of  local  supply 

7.  Remarks. 


164  PHYSICAL  GEOGRAPHY  MANUAL 

EXERCISE  LXIX 
DECOMPOSING  AGENTS 

Pakt  I 

What  effect  does  heat  have  upon  brass  and  iron  ?  (See  Exer- 
cise XXXI.)  To  ascertain  whether  they  are  equally  affected, 
heat  a  bar  consisting  of  one  brass  plate  and  one  iron  plate. 
What  change  of  shape  do  you  observe  ?  Which  plate  expands 
more  upon  being  heated?  Feldspar  and  quartz  expand  une- 
qually when  heated.  What  effect  will  change  of  temperature 
probably  have  upon  the  texture  of  granite?  Will  a  granite 
monument  endure  longer  in  a  climate  of  uniform  or  changeable 
temperature? 

Part  II 

Examine  granite  having  a  growth  of  lichens  on  the  surface. 
Which  would  dry  more  quickly  if  thoroughly  wet,  a  piece  of 
granite  with  a  covering  of  lichens  or  a  piece  without  lichens? 
(If  in  doubt,  try  it.)  How  will  this  affect  the  rate  of  weather- 
ing of  granite?  How  do  lichens  cling  to  the  granite?  Will 
this  aid  or  retard  weathering?  The  decay  of  the  roots  makes 
an  acid  which  the  water  carries  into  the  granite.  Will  the 
presence  of  this  acid  aid  or  retard  weathering? 

Part  III 

Write  a  paper  telling  how  each  of  the  following  aids  in  the 
process  of  rock  decay. 

1.  Oxidation.    (See  Exercise  Xl.t 

2.  Vegetation  and  roots. 

3.  Burrowing  animals. 

4.  Water.    (See  Exercise  LII.) 

5.  Rivers,  waves,  glaciers.  (See  Exercises  XXXII  and 
LIX.) 


IRRIGATION  165 

EXERCISE  LXX 

IRRIGATION 

Write  a  paper  on  one  or  more  of  the  following  phases  of 
irrigation. 

1.  Irrigation  in  the  United  States. 

2.  Extent  of  irrigation. 
3.'  Antiquity  of  irrigation. 

4.  Metliods  of  elevating  water  for  irrigation. 

5.  Methods  of  storing  water  for  irrigation. 

6.  Methods  of  distributing  water  for  irrigation. 

7.  Methods  of  measuring  water  for  irrigation. 

8.  Losses  of  water  in  irrigation. 

(State  books  read  and  authorities  consulted  in  writing  your 
paper.) 


^    p 


.166 


APPENDIX 


LIST  OF  TEXT-BOOKS 

Davis,  Physical  Geography.    Ginn  &  Company.    1899. 

Davis,  Elementary  Physical  Geography.  Ginn  &  Company. 
1902. 

Dryer,  Lcssotis  in  Physical  Geography.  American  Book  Company. 
1901. 

Gilbert  and  Brigliam,  A71  Introduction  to  Physical  Geography. 
D.  Appleton  &  Co.    1902. 

Redway,  Elementary  Physical  Geography.  Charles  Seribner's 
Sons."  1900. 

Tarr,  New  Physical  Geography.    The  Macmillan  Company.    1904. 

LIST  OF  REFERENCE  BOOKS 

Bailey,  Principles  of  Agriculture.    Macmillan.     $1.25. 

Beal,  Seed  Dispersal.     Ginn.    50  cents. 

Hergen,  Poundafions  of  Botany.     Ginn.     $1.50. 

Brigham,  Geographic  Influences  in  American  History.  Ginn. 
$1.75. 

California  Water  and  Forest  Association,  Shonld  the  Forests  be 
Preserved  ?  California  Water  and  Forest  Association,  Mills  Build- 
ing, San  Francisco.    Free. 

Coulter.  Pla7it  Stvdies.     Appleton.     $1.25. 

Crosby,  Common  Minerals  and  Rocks.    Heath.    40  cents. 

Davis,  Elementary  Meteorology.    Ginn.    $2.50. 

Dodge,  A  Reader  in  Physical  Geography  for  Beginners.  Long- 
mans.   70  cents. 

Fairbanks,  Rocks  and  Minerals.  Educational  Publishing  Com- 
pany.   60  cents. 

Fairbanks,  Western  United  States.    Heath.    60  cents. 

167 


168  PHYSICAL  GEOGEAPHY  MANUAL 

Garriott,  Long-Range  Weather  Forecasts.  Bulletin  No.  322,  United 
States  Weather  Bureau. 

Gifford,  Practical  Forestry.    Appleton.    $1.00. 

Harrington,  About  the  Weather.    Appleton.    60  cents. 

Heilprin,  The  Earth  and  Its  Story.    Silver.    $1.00. 

Jordan,  Science  Sketches.    McClurg.    $1.50. 

Jordan  and  Kellogg,  Animal  Life.    Appleton.    $1.20. 

Kenealy,  Weather  Bureau  Stations  and  their  Duties.  United  States 
Weather  Bureau.    Free. 

King,  Irrigation  and  Drainage.    Macmillan.    $1.50. 

King,  The  Soil.    Macmillan.    75  cents. 

Kinney,  Forest  and  Water.  Post  Publishing  Company,  Los 
Angeles.    $1.50. 

Mead,  Irrigation  Institutions.    Macmillan.    $1.25. 

Merriam,  Life  Zones,  and  Crop  Zones  of  the  United  States.  Bul- 
letin No.  10,  United  States  Biological  Survey.    Free. 

Moore,  Bacteria  and  the  Nitrogen  Problem.  Reprint  from  Year 
Book  of  the  United  States  Department  of  Agriculture  for  1902.    Free. 

Moore,  Climate,  Its  Physical  Basis  and  Controlling  Factors.  Bul- 
letin No.  34,  United  States  Department  of  Agriculture.  (Weather 
Bureau.)    Free. 

"MmT,  Mountains  of  California.    Century  Company.    $1.50. 

Newcomb,  Elements  of  Astronomy.  American  Book  Company. 
$1.00. 

Osterhout,  Experiments  toith  Plants.    Macmillan.     $1.25. 

Pinchot,  Primer  of  Forestry,  Parts  I  and  11.  Bulletin  No.  24, 
Parts  I  and  II,  United  States  Bureau  of  Forestry.    Free. 

Roth,  A  First  Book  of  Forestry.    Ginn.    75  cents. 

Russell,  Glaciers  of  North  America.    Ginn.    $2.00. 

^vi?,s&\\,  Lakes  of  North  America.    Macmillan.    $1.50. 

Russell,  North  America.    Appleton.    $2.50, 

^\x%^e\\,  Bwers  of  North  America.    Putnam.    $2.00. 

Russell,  Volcanoes  of  North  America.    Macmillan.    $4.00. 

^\\2i\ev,  Aspects  of  the  Earth.    Scribner.    $2.50. 

Shaler,  First  Book  in  Geology.    Heath.    45  cents. 

^\\QXev,  Outlines  of  the  Earth'' s  History.    Appleton.    $1.75. 

Shaler,  Sea  and  Land.    Scribner.    $2.50. 

Shaler,  Story  of  Our  Continent.    Ginn.    75  cents. 


APPENDIX 


169 


Tarr,  Economic  Geology  of  the  United  States.    Macmillan.    $3.50. 
Tarr,    Elementarij  Geology.    Macmillan,  $1.40. 
Toumey,  Relation  of  Forests  to  Stream  Flow.    Reprint  from  Year 
Book  of  the  United  States  Department  of  Agriculture  for  1903.    Free. 
Waldo,  Elementary  Meteorology.  American  Book  Company.  $1.50. 


Fig.  45.    Pupils'  Work  Table  in  the  Laboratory 

Height,  .36  inches  ;  width,  48  inches ;  length,  12  feet.    Knee  space,  18  inches 
wide ;  stool,  24  inches  in  height 

Ward,  Report  on  the  Petrified  Forests  of  Arizona.  United  States 
Department  of  the  Interior. 

Westgate,  Reclamation  of  Cape  Cod  Sand  Dunes.  Bulletin  No. 
65,  United  States  Department  of  Agriculture.  (Bureau  of  Plant 
Industry.) 

Winchell,  Walks  and  Talks  in  the  Geological  Field.  Jacobs. 
$1.00. 

Winslow,  Principles  of  Agriculture.  American  Book  Company. 
60  cents. 

Young,  Lessons  in  Astronomy.    Ginn.    $1.25. 


170  PHYSICAL  GEOGRAPHY  MANUAL 


LIST  OF  GOVERNMENT  MAPS 

Topographic  Atlas,  United  States  Geological  Survey,  Folio  No.  1 ; 
25  cents.    Same,  Folio  No.  2 ;  25  cents. 

Canyon  (Wyo.)  sheet,  topographic  map  of  the  United  States  Geo- 
logical Survey  ;  3  cents  wholesale.^ 

Doylestown  (Penn.)  sheet,  topographic  map  of  the  United  States 
Geological  Survey ;  3  cents. 

Assembled  topographic  sheets,  showing  plateau  and  divides  of 
the  Yellowstone  National  Park,  Wyoming,  as  follows  :  Gallatin, 
Canyon,  Shoshone,  Lake  ;  4  sheets,  3  cents  each. 

Assembled  topographic  sheets,  showing  Green  Bay  (Wis.)  lobe  of 
ancient  glacier  as  follows  :  Madison,  Sun  Prairie,  Waterloo,  Water- 
town,  Oconomowoc,  Waukesha,  Milwaukee,  Evansville,  Stoughton, 
Koshkonong,  Whitewater,  Eagle,  Muskego,  Bay  View,  Brodhead, 
Janesville,  Shopiere,  Delavan,  Geneva,  Silver  Lake,  Racine;  21 
sheets,  3  cents  each. 

Assembled  topographic  sheets,  showing  barrier  beaches  off  the 
coast  of  New  Jersey,  as  follows :  Sandy  Hook,  Asbury  Park, 
Barnegat,  Long  Beach,  Little  Egg  Harbor,  Atlantic  City ;  6  sheets, 
6  cents  each. 

Assembled  topographic  sheets,  showing  Cape  Cod  (Mass.),  as 
follows :  Provincetown,  Wellfleet,  Chatham,  Yarmouth  ;  4  sheets, 
3  cents  each. 

Pilot  charts  of  the  North  Atlantic  ocean.  United  States  Coast 
and  Geodetic  Survey ;  10  cents  each.  Same,  North  Pacific  ocean ; 
10  cents  each. 

Tide  Tables  for  Pacific  (or  Atlantic)  ports  for  current  year, 
United  States  Coast  and  Geodetic  Survey ;  10  cents. 

Map  showing  magnetic  declination  in  the  United  States,  United 
States  Coast  and  Geodetic  Survey. 

United  States  Coast  and  Geodetic  Survey  maps  (50  cents  each),  as 
follows : 

1  The  Geological  Survey  uses  the  term  wholesale  to  include  lots  of  one  hundred 
or  more  maps  purchased  at  one  time.  The  wholesale  price  of  topographic  maps 
is  given  in  each  case.     Single  maps  cost  5  cents. 


APPENDIX 


171 


109  Boston  bay, 

110  Cape  Cod  bay. 
120   New  York  bay. 

194  and  195   Mississippi  river  to  New  Orleans. 
5100   San  Diego  to  Santa  Monica. 
5581    San  Francisco  entrance. 


Fig.  46.    Teacher's  Cabinet  Table  in  the  Laboratory 

Large  drawers  at  the  right,  to  receive  large  maps  lyiug  flat,  48  X  48  X  6  inches; 
iipjier  drawers  at  the  left,  to  receive  topographic  maps  (with  partitions  for 
mineral  and  other  specimens),  22  X  22  X  5  inches;  lower  drawers  at  the  left, 
to  receive  larger  specimens  and  the  smaller  pieces  of  apparatus,  22  X  10  X  10 
inches 

Weather  Bureau  publications,  as  follows  : 

Daily  weather  map  from  Washington  ;  free. 
Daily  weather  map  from  local  station  ;  free. 
Average    annual  precipitation  in   the  United  States  (with 

maps),  a  reprint  from  the  Monthly  Weather  Retnew  for 

April,  1902. 

Wall  map  of  the  United  States,  United  States  Department  of  the 
Interior;  $1.00. 


172  PHYSICAL  GEOGRAPHY  MANUAL 

LIST  OF  APPARATUS  AND  SUPPLIES 

Note.  This  list  includes  only  such  apparatus  and  supplies  as  are 
specifically  referred  to  in  Part  II  of  this  manual.  It  will  be  observed  that 
a  large  part  is  probably  already  in  the  possession  of  the  average  high 
school,  and,  if  necessary,  the  teacher  of  physical  geography  can  draw  upon 
the  departments  of  physics,  chemistry,  mathematics,  and  geology  for 
tliese  things. 

Gyroscope  (may  be  homemade),  8-inch  globe  with  movable 
meridian,  pasteboard  circle  to  fit  globe,  wet  and  dry  bulb  ther- 
mometer, maximum  and  minimum  thermometer,  barometer,  rain 
gauge,  slated  globe. 

Rotating  machine  with  brass  rings,  specific-gravity  balances  and 
box  of  weights,  Bunsen  burner,  blowpipe,  air  pump,  apparatus  and 
materials  for  generating  oxygen,  same  for  generating  carbon  dioxide, 
pneumatic  trough,  steel  wool,  watch  crystals,  ether,  alcohol,  tri- 
angular glass  prism,  bar  magnet,  mounted  magnetic  needle,  Torri- 
cellian tubes,  mercury,  test  tubes,  beaker,  rubber  stoppers,  glass 
tubing,  adjustable  pinchcock,  mortar  and  pestle,  evaporating  dish, 
funnel,  filter  paper,  hydrochloric  acid,  apparatus  for  distilling 
water,  hydrometer. 

Lead  bullet,  string,  old  electric-light  bulb,  empty  bottles,  candle, 
corks,  tumbler  with  straight  sides,  V-shaped  trough,  teakettle,  yard- 
stick, brightly  polished  metal  cup,  ice,  glass  jar  with  straight  sides, 
soap,  mirror,  box  of  tacks,  blocks  of  wood,  pointer,  sand,  lever  with 
wire  and  rubber  band,  salt,  clay,  sand,  gravel,  alum,  photographers' 
hypo,  sea  water. 

Mineral  and  rock  specimens,  about  forty  different  kinds,  sufii- 
cient  in  number  to  supply  pupils  of  largest  class  when  working 
in  pairs. 


INDEX 


Abrasion,  20 

Absolute  humidity,  6,  7,  71 
Alluvial  cones,  23,  112 
Ancient  glaciers,  29,  128 
Angle  of  inclination  of  earth's  axis, 
4,  63 

of  noon  elevation  of  sun,  6,  61 
Animals,  46-51 

changes  in,  48 

distribution  of,  47 

economic  value  of,  49 

migrations  of,  47 
Anticyclones,  10,  83-92 
Apparatus,  list  of,  172 
Argentina,  rainfall  of,  93 
Artesian  wells,  33 
Assembled    topographic   sheets,    117, 

128,  151,  170 
Assorting  power  of  water,  20,  105 
Atlantic  City  (N.J.)  topographic  sheet, 

150 
Atmosphere,  6-8 

constituents  of,  6,  67 

general  movements  of,  9,  87 

physical  properties  of,  6,  66 

saturated,  6,  7,  70,  72 

weight  and  pressure  of,  6,  9,  66 
Atmospheric  pressure,  9,  66 
Axis  of  the  earth,  4,  58 

Bad  lands,  21 
Barometer,  9,  83-92 

movements  of  low,  10,  91 
Barrier  beaches,  38,  150 
Barriers  to  migration,  47,  48 
Base  level  of  erosion,  23,  24,  119 
Basins,  drainage,  24,  120 

interior,  31,  133-135 


Beaches,  38,  149,  150 
Beheading  of  a  stream,  24,  121 
Boothbay  (Me.)  topographic  sheet,  152 
Building  stone,  43,  163 
Buttes,  21 

Calms,  9,  87,  97,  98 

Canyon  of  the  Yellowstone,  117 

Canyon  (Wyo.)  topographic  sheet,  107, 

114 
Canyons,  21 

Capacity  for  water  vapor,  70,  71 
Carbon,  40,  41,  157,  158,  159 
Carbon  dioxide,  68,  136,  137,  158 
Cardinal  points,  60 
Caverns,  32,  137 
Centrifugal  force,  67 
Centripetal  force,  57 
Charleston  (W.  Va.)  topographic  sheet, 

117 
Chile,  rainfall  of,  93 
Circle  of  illumination,  59 
Clay,  44,  105,  159,  160 
Climate,  13-15 

changes  of,  14 

factors  of,  13 

relation  of,  to  life,  15 

zones  of,  13,  96 
Climatic  regions  of  the  United  States, 

14,  97,  98 
Clinometer,  61 
Clouds,  7 
Coal,  40,  41,  157 
Coast  forms,  37-39 
Coast  outlines  and  civilization,  39 
Coastal  plains,  18 
Coasts,  drowned  and  elevated,  152 

rising  and  sinking,  38 


173 


174 


PHYSICAL  GEOGRAPHY  IMANUAL 


Colorado  river,  24,  25,  134,  135 

Colors  of  sky,  75,  76 

Combustion,  67,  68 

Compass,  76 

Condensation,  6,  69 

Cones,  alluvial,  23,  112 

Consequent  streams,  131 

Continental  glaciers,  28,  128 

Continental  outlines,  37 

Contour  interval,  99 

Contour  lines,  19,  99 

Contour  maps,  19,  101 

Coral  reefs,  30 

Corrasion,  20 

Crater,  26,  126 

Crater  lake  (Ore.)  special  topographic 

sheet,  126 
Creep,  19 

Crescent  beaches,  37,  38,  150 
Crevasse,  glacial,  28 

in  a  levee,  22,  108 
Crystals,  136 
Cucamonga  (Cal.)  topographic  sheet, 

112 
Currents,  35,  142 
Cyclones,  10,  88-91 

forward  movements  of,  91 

precipitation  in,  89 

temperatures  in,  90 

tropical,  11 

winds  in,  88 

Day  and  night,  length  of,  4,  59 
Dead  sea,  135 
Debris  cones,  23,  112 
Declination,  magnetic,  77 
Decomposing  agents,  43,  164 
Deltas,  23 

Density  of  sea  water,  34,  139 
Deserts,  29 
Dew,  7,  71,  72 

Disintegration  and  erosion,  19-21 
Dismal  swamp,  133 
Distribution  of  animals  and  plants,  47 
of  man,  61 


Divides,  migration  of,  24,  120 

Doldrums,  87 

Donaldsonville (La.)  topographic  sheet, 

107 
Doylestown  (Pa. )  topographic  sheet,  120 
Drainage,  imperfect,  30-31,  115 

perfect,  23,  118 
Drainage  areas  of  the  United  States,  24, 

120 
Drowned  coasts,  38,  152 
Drumlins,  29,  128 
Dunes,  29,  151 

Eagle  (Wis.)  topographic  sheet,  129 
Earth  among  planets,  3-6 

as  a  whole,  15 

direction  of  axis  of,  4,  58 

form  of,  4,  56 

motions  of,  4 

movements  of  crust  of,  16 

structure  of,  15-19 
Earthquakes,  27 
Economic  importance  of  animals,  49 

of  atmosphere,  6 

of  building  stone,  43,  163 

of  climate,  15,  96 

of  coast  lines,  39 

of  deserts,  29 

of  fertilizers,  45 

of  forests,  45,  49 

of  geography,  50 

of  irrigation,  45,  165 

of  magnetism,  8,  76,  77 

of  minerals,  39,  155,  157 

of  mountains,  18 

of  plants,  49 

of  rivers,  25 

of  sand  dunes,  30 

of  the  sea,  36,  145-147 

of  snow,  7 

of  soil,  44 

of  topography,  108,  111,  118,  119, 
120 

of  volcanoes,  26 

of  weather,  11 


INDEX 


175 


Electricity,  8 
Elevated  coasts,  38,  152 
Equinox,  59,  65 
Erosion,  19-21 

base  level  of,  119 
Evaporation,  6,  69,  136,  137 
Evening  and  morning  glow,  76 
Extinct  lakes,  31,  134 
Extinct  volcanoes,  123,  126 

Fans,  alluvial,  23,  112 

Fertilizei"s,  45 

Fiords,  152 

Floes,  36 

Flood  plains,  22,  107 

Fog,  7 

Forestry  as  related  to  soil,  45 

Forests,  49 

Fossils,  41,  156 

Fragmental  rocks,  42,  160 

Freezing  mixture,  104 

Frost,  7 

Gas,  41 

Geographical  factors  in  the  life  of  civi- 
lized peoples,  50 
Geysere,  33 
Glaciation,  topographic  forms  due  to, 

29,  128 
Glaciers,  alpine,  27,  127,  128 

ancient,  29,  128-131 

continental,  28 

on  Mt.  Shasta,  127 

piedmont,  28 
Grand  river,  113 
Granite,  42,  159 
Gravity,  57,  140 
Great  plains,  rainfall  of,  93 
Great  Salt  lake,  31,  134 
Ground  water,  32-34,  135-138 
Gulf  of  California,  134 
Gulf  stream,  142 
Gyroscope,  58 

Hachures,  19,  99 


Hail,  7 

Harbors,  39,  154 
Hardness  of  a  mineral,  155 
Headlands,  37,  148 
Heat,  68,  69,  70,  104,  164 
High  barometer,  10,  83-92 
Humidity,  6,  70 
Hurricanes,  11 

Ice,  104,  144 

Icebergs,  36,  144 

Igneous  rocks,  42 

Insolation,  8,  9 

Interior  basins,  31 

Iron,  39,  40,  68,  69,  155,  159 

Irrigation,  45,  165 

Islands,  37 

Isobars,  9,  83 

Isohyetals,  93 

Isotherms,  8,  77,  82 

Kanawha  river,  117 

Lagoons,  23 
Lakes,  30,  131 

extinct,  31,  134 

salt,  31 
Land  breeze,  12 
Lauds,  15 
Landslides,  27 
Latitude,  5,  65 
Lava,  26,  123 
Levee,  107,  108 
Life,  conditions  of,  46 
Light,  8,  74 
Limestone,  40,  41,  156 
Load  of  a  stream,  20 
Longitude,  5 
Low  barometer,  10,  83-92 

Magnetic  declination,  77 

Magnetism,  8,  76 

Man,  46-51 

and  nature,  50 
distribution  of,  51 


176 


PHYSICAL  GEOGRAPHY  MANUAL 


Man,  races  of,  51 

Maps,  assembled  topographic,  117, 128, 
151,  170 

contour,  19,  100,  101 

government,  170 

hachure,  19,  100 
Marshall  (Mo.)  topographic  sheet,  110 
Marshes,  30 
Mature  region,  117 
Meanders,  23,  110 
Merced  river,  108 
Mesas,  21 

Metamorphic  rocks,  42 
Migration  of  plants  and  animals,  47, 
48 

of  dividers,  24,  120 

of  waterfalls,  106,  115 
Minerals  and  rocks,  39-43,  155-164 
Mississippi  river,  24,  25,  107 
Missouri  river,  24,  25,  110 
Moon,  5,  64,  140 
Moraines,  28,  127,  129 
Mt.  Mazama,  126 
Mt.  Shasta,  127 
Mt.  Taylor  (N.M.)  topographic  sheet, 

123 
Mountains,  causes  of,  16 

economic  aspects  of,  18 

kinds  of,  17 

life  history  of,  17 


Organically  formed  rocks,  40,  156,  157 
Oxbows,  23 
Oxidation,  68 
Oxygen,  67 

Percolating  water,  32 
Petroleum,  41 
Piedmont  glaciers,  28 
Plains,  18 
Planets,  3,  55 
Plant  zones,  47 
Plants,  46,  51 

changes  in,  48 

economic  value  of,  49 

migrations  and  barriers,  47 
Plateaus,  18 

ancient,  118,  119 

of  Yellowstone  park,  117 

volcanic,  123 
Pocket  beach,  37,  38,  150 
Pressure,  atmospheric,  9,  66 
Profile  from  contour  map,  102 

from  hypsometric  map  of  United 
States,  98 

Kaces  of  mankind,  51 

Rain,  7 

Rainbow,  8,  75 

Rainfall,  10,  13,  93,  95,  96,  98 

in  cyclones  and  anticyclones,  10, 


Natural  gas,  41 

Nature  and  man,  50 

Nitrogen,  67 

Noon,  61 

Norfolk  (Va.)  topographic  sheet,  133 

North  and  south  line,  60 

North  star,  58,  60 

Ocean,  32-36 
life  in,  36 
Ocean  currents,  35-142 
Ocean  water,  34 
Old  region,  119 
Ores,  39,  165 


in  equatorial  regions,  96 

on  the  Pacific  coast,  93,  98 
Range  of  temperature,  13,  97 

of  tides,  35,  140 
Rapids,  21 
Reefs,  coral,  30 

sand,  150,  151 
Reference  books,  167 
Refraction,  8,  74 
Region  in  maturity,  23,  117 

in  old  age,  23,  119 

in  youth,  23,  114 
Relative  humidity,  6,  7,  71,  73 
Relief,  representation  of,  19,  98-102 


INDEX 


177 


Revolution  of  earth,  4,  59 

of  moon,  64 
River  piracy,  24,  121 

systems,  24 
Rivers,  21-25 

economic  importance  of,  25 

life  history  of,  23,  120 

typical,  24 
Rock  waste,  10-21,  105 
Rocks,  disintegration  of,  19 

fragmental,  42,  100 

igneous,  42 

metamorphic,  42 

organically  formed,  40,  156,  157 

volcanic,  26,  123 
Rotation  of  earth,  4,  57,  58 

Sailing  routes,  87,  88,  145 
Salt  lakes,  31,  134 
Sal  ton  sea,  134 
Sand  dunes,  29 
Scale  of  hardness,  155 
Sea,  and  man,  36,  145 

bottom,  34 

breeze,  12 

caves,  37,  38,  149 

encroachment    of,    37,     148-150, 
152,  154 

encroachment  on,  38,  150-154 

water,  34,  139 
Seasons  of  the  year,  4,  5,  59 
Sedimentary  rocks,  42,  160 
Shasta  (Cal.)  special  topographic  sheet, 

127 
Sky,  color  of,  8,  75,  76 

evening  and  morning  glow  of,  8, 
76 
Snow,  7 
Soil  as  affected  by  forests,  45 

fertility  of,  44 

kinds  of,  44 

residual,  19 
Soils,  43-46 
Solar  system,  3,  55 
Solids  in  solution,  32,  33,  136 


Solstice,  59 

Solution,  135 

Soundings,  34 

Specific  gravity,  122,  123,  144, 156, 157 

Spectrum,  8,  75 

Springs,  32 

Stalactites,  32,  137 

Stars,  distances  of,  from  earth,  3,  56 

Storms,  8-12 

Stratified  rocks,  42,  160 

Streak  of  a  mineral,  155 

Struggle  for  existence,  48,  49 

Sun,  5,  61 

Sun  Prairie  (Wis.)  topographic  sheet, 

128 
Sunrise  and  sunset  curves,  63 
Swamps,  30,  133 

Talus,  19 
Temperature,  8 

average,  77 

range  of,  97 
Terraces,  22 
Text-books,  167 
Thunderstorms,  12 
Tides,  35,  140 
Topographic  maps,  170 
Tornadoes,  11 
Trade  winds,  10,  87 
Tropical  cyclones,  11 

Underground  waters,  32-34,  135-138 

Valleys,  22 

Veins,  33,  137 

Volcanic  peaks,  plateaus,  and  necks, 

26,  123 
Volcanic  phenomena,  26 
Volcanic  rocks,  26,  123 
Volcanoes,  extinct,  123,  126 
typical,  25 

Water  vapor,  6,  7,  69-74 
Waterfalls,  21,  106 
Waves,  35 


178 


PHYSICAL  GEOGRAPHY  MANUAL 


Weather  forecasting,  11,  92 
Weather  maps,  171 
Weather  observations,  86 
Weathering,  43,  44,  102 

and  soils,  43-46 
Winds,  8-12,  87 

local,  12 

westerly,  87 


Yellowstone  river,  107,  114 
Yellowstone  (Wyo.)  topographic  sheet, 

107,  114 
Young  region,  114 

Zones  of  climate,  13,  96 

of  vegetation  surrounding  a  lake, 
133 


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